研究者詳細 - 寺西　貴志

論文 - 寺西　貴志

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Fabrication of Mullite Based Porous Ceramics with Favorable Creep Resistance Utilizing Superplastically Foaming Method

Ryotaro Yokota, Sakiho Arizuka, Wakuya Miyamoto, Shinya Kondo, Takashi Teranishi, Akira Kishimoto

Journal of the Japan Society of Powder and Powder Metallurgy 72 ( Supplement ) S761 - S766 2025年3月

Permittivity and remanent polarization contributions to the electrocaloric effect in (Ba, Sr)TiO3 under unipolar field

Yukiya Tanaka, Ryo Iguchi, Takashi Teranishi, Shinya Kondo, Akira Kishimoto

Applied Physics Letters 126 ( 13 ) 2025年3月

掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

The electrocaloric effect (ECE)-induced temperature change (ΔT) in (Ba, Sr)TiO3-based ferroelectrics under unipolar electric fields was analyzed from the separate contributions of the dielectric constant (ε) and remanent polarization (Pr) based on the Maxwell relation. Consideration of the contributions of both ε and Pr is particularly important in a unipolar electric field operation, such as on/off field switching used in device applications. Direct ΔT measurements were also performed based on the lock-in thermography technique to verify the accuracy of the ΔT intensity estimated by the indirect method. The indirect and direct ΔT values were largely consistent. The ΔT intensity near the peak temperature of ΔT was dominated by the Pr contribution; a large ∂Pr/∂T was necessary to increase the overall ΔT magnitude. In contrast, a large ∂ε/∂T was essential to expand the operating temperature range of ΔT at temperatures higher than the dielectric maximum temperature. Quantitative understanding of the contributions of both ε and Pr to ΔT in unipolar electric fields is expected to guide the search for materials with a superior ECE.

DOI： 10.1063/5.0259805

Dynamic domain motion enhancing electro-optic performance in ferroelectric films

Shinya Kondo, Kazuki Okamoto, Osami Sakata, Takashi Teranishi, Akira Kishimoto, Takanori Nagasaki, Tomoaki Yamada

Applied Physics Letters 126 ( 1 ) 2025年1月

掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

With the rapid advancement of information technology, there is a pressing need to develop ultracompact and energy-efficient thin-film-based electro-optic (EO) devices. A high EO coefficient in ferroelectric materials is crucial. However, substrate clamping can positively or negatively influence various physical properties, including the EO response of these films, thus complicating the development of next-generation thin-film-based devices. This study demonstrates that reversible dynamic domain motion, achieved through substrate clamping, significantly enhances the EO coefficient in epitaxial ferroelectric rhombohedral Pb(Zr, Ti)O3 thin films, where the (111) and (111¯) domains coexist with distinct optical axes. In principle, this approach can be applied to different film-substrate systems, thereby contributing to the advancement of sophisticated EO devices based on ferroelectrics.

DOI： 10.1063/5.0244707

Doping Rare Earth Dependent Mechanical Strength Improvement on Reduction of Ceria Based Solid Electrolytes

Taiga UEHARA, Shinya KONDO, Takashi TERANISHI, Akira KISHIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy 71 ( 11 ) 529 - 533 2024年11月

Colossal Dielectric Constant of Nanocrystalline/Amorphous Homo-Composite BaTiO3 Films Deposited via Pulsed Laser Deposition Technique

Shinya Kondo, Taichi Murakami, Loick Pichon, Joël Leblanc-Lavoie, Takashi Teranishi, Akira Kishimoto, My Ali El Khakani

Nanomaterials 14 ( 20 ) 1677 - 1677 2024年10月

掲載種別：研究論文（学術雑誌）出版者・発行元：MDPI AG

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO3 (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (εr) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (Td) over a wide range (300–800 °C), we identified Td = 550 °C as the optimal temperature for growing BTO films with an εr as high as ~3060 and a tan δ as low as 0.04 (at 20 kHz). High-resolution transmission electron microscopy revealed that the PLD-BTO films consist of BTO nanocrystals (~20–30 nm size) embedded within an otherwise amorphous BTO matrix. The impressive dielectric behavior is attributed to the combination of highly crystallized small BTO nanograins, which amplify interfacial polarization, and the surrounding amorphous matrix, which effectively isolates the nanograins from charge carrier transport. Our findings could facilitate the development of next-generation integrated dielectric devices.

DOI： 10.3390/nano14201677

Polarization at the compositional interface in Nb-doped metastable TiO₂-SnO₂ solid solutions

Takashi Teranishi, Junsuke Satake, Shinya Kondo, Akira Kishimoto

Japanese Journal of Applied Physics 63 ( 7 ) 07SP05 - 07SP05 2024年7月

掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing

Abstract

Polarization architecture was incorporated into metastable Nb-doped TiO₂-SnO₂ to deliver electron accumulation at the localized TiO₂-SnO₂ compositionally fluctuating interface. Specimens were quenched from various holding temperatures to ambient temperatures in air to avoid bimodal decomposition into TiO₂ and SnO₂ endmembers. At the lowest sintering temperature of 1,400 °C, the mixed phase containing TiO₂- and SnO₂-rich compositions existed as an intermediate state to the single-phase solid solution. The phase boundary became more ambiguous with increasing sintering temperatures, and the compositional fluctuation size reduced to single nanometers at 1,500 °C. The permittivity due to the interfacial polarization, ε _interface, increased steadily with increasing sintering temperature. The larger ε _interface values at higher temperatures are attributed to the greater density of the compositionally fluctuating phase interface, which leads to greater electron accumulation at the energy barrier between the two semiconducting layers.

DOI： 10.35848/1347-4065/ad5e8d

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ad5e8d/pdf

Enhanced Charge Accumulation in Activated Carbon via the Dielectric Interface

Yuji Toyota, Takashi Teranishi, Kosuke Fukui, Masakuni Takahashi, Ji Qiuyu, Shinya Kondo, Masanobu Nakayama, Akira Kishimoto

ACS Applied Energy Materials 7 ( 4 ) 1440 - 1447 2024年2月

外場としてのミリ波を援用した高温電気化学デバイスの特性変化

Takuro FUJIWARA, Takashi TERANISHI, Akira KISHIMOTO, Seiichi SUDA

Journal of the Japan Society of Powder and Powder Metallurgy 70 ( 9 ) 387 - 391 2023年9月

負膨張材料を分散させた表面層を持つセラミックス積層体の耐熱衝撃性

Takaya UENO, Shinya KONDO, Takashi TERANISHI, Akira KISHIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy 70 ( 8 ) 376 - 379 2023年8月

Polarization contributions to DC bias characteristics of nanograined BaTiO₃-based ceramics

Takashi Teranishi, Ruku Ozaki, Shinya Kondo, Akira Kishimoto

Japanese Journal of Applied Physics 62 ( SM ) SM1015 - SM1015 2023年8月

掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing

Abstract

The domain configuration contributions to the DC bias characteristics of nanograined BaTiO₃ were clarified. Domain boundaries became more ambiguous with decreasing grain size (g.s.), whereas domain patterns partially vanished because of the reduction in BT ferroelectricity, in the g.s. range <1 μm. Additionally, intergranular stress increased with decreasing g.s., resulting in crystal lattice hardening in the vicinity of the domain walls (DWs) and suppression of dipole fluctuations in the DWs. These domain structural variations with the domain size (d.s.) reduced permittivity in the absence of a DC electric field, resulting in improvements in permittivity depressions in an electric field (Δε). Magnesium substitution slightly decreased the d.s. The increase in DW density upon Mg loading implied defect pairs, ${ { \rm{Mg } } }_{ { \rm{Ti } } }^{"}$–${ { \rm{V } } }_{ { \rm{o } } }^{\bullet \bullet },$ which acted as new DW pinning centers, thereby subdividing the DWs. The Δε notably improved via Mg loading, because a defect pair effectively pins the DWs under the electric field.

DOI： 10.35848/1347-4065/ace6a8

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ace6a8/pdf

Spinodal decomposition-derived giant polarization in TiO2–SnO2 generated from a metastable phase 査読

Takashi Teranishi, Hideki Matsui, Shinya Kondo, Akira Kishimoto

Journal of Applied Physics 133 ( 17 ) 2023年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：{AIP} Publishing

<jats:p>Spinodal decomposition (SD) was incorporated into Nb-doped metastable TiO2–SnO2 to achieve giant interfacial polarization. The dielectric characteristics were analyzed using an equivalent circuit involving electron migration, where the SD bulk is given by the universal dielectric response relation. Both the Nb–TiO2 and the Nb–SnO2 layers showed semiconductive behaviors. With increasing SD treatment temperature, the SD volume fraction increased, as did cation interdiffusion at the SD interface, resulting in a large dielectric loss. The optimal SD temperature was determined as 1100 °C, where the Maxwell–Wagner capacitance showed a very high value of 44.6 μF corresponding to the permittivity at the lowest frequency exceeding 106. Such colossal polarization was considered due to an accumulation of trapped electrons at the Schottky barrier at SD layers with different conductivities.</jats:p>

DOI： 10.1063/5.0144782

Direct measurement of electrocaloric effect based on multi-harmonic lock-in thermography

Ryo Iguchi, Daisuke Fukuda, Jun Kano, Takashi Teranishi, Ken-ichi Uchida

Applied Physics Letters 122 ( 8 ) 2023年2月

掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

We report on a direct measurement method for electrocaloric effects, the heating/cooling upon application/removal of an electric field in dielectric materials, based on a lock-in thermography technique. By use of sinusoidal excitation and multi-harmonic detection, the actual temperature change can be measured by a single measurement in the frequency domain even when the electrocaloric effect shows a nonlinear response to the excitation field. We demonstrated the method by measuring the temperature dependence of the electric-field-induced temperature change in two Sr-doped BaTiO3 systems with different ferroelectric-paraelectric phase transition temperatures, where we introduce the procedure for extracting the pure electrocaloric contribution free from heat losses and Joule heating due to leakage currents. This method can be used irrespective of the type of dielectric material and enables simultaneous estimation of the polarization change and power dissipation during the application of an electric field, making it a convenient imaging measurement method for the electrocaloric effect.

DOI： 10.1063/5.0137686

Density Functional Theory and Machine Learning-Based Analyses for Improved Surface Stability of a BaTiO3-Coated LiCoO2 Positive Electrode Material

Kunihiro Ishida, Naoto Tanibata, Hayami Takeda, Masanobu Nakayama, Takashi Teranishi, Naoki Watanabe

PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS 259 ( 9 ) 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

The application of oxide coating on the surfaces of active cathode materials is an effective method for improving the electrochemical durability of lithium-ion batteries because it suppresses oxygen gas release from the surface of the cathode material. This report summarizes a study conducted on verifying the suppression of oxygen release from a LiCoO2 cathode material using BaTiO3 (BT), which has recently attracted attention as a new coating material. The use of first-principles calculations and machine learning as verification methods is described. In addition to the discussion of interfacial properties based on atomic- and electronic-level considerations, comprehensive verification of the interface with several junction patterns is described. The verification results suggest that the desorption of oxygen from the surface of the active material is hindered by the oxide coating, indicating the effectiveness of BT as a coating material.

DOI： 10.1002/pssb.202100526

Electric Potential Mapping of All-Solid-State Lithium Ion Batteries using A Terahertz Chemical Microscope

Ryota Tomie, Taketo Yamaguchi, Masashi Shimizu, Kashu Hamada, Takashi Teranishi, Hidetoshi Nose, Masaki Kobayashi, Jin Wang, Kenji Sakai, Toshihiko Kiwa

2022 47TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ 2022) 2022年8月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A terahertz (THz) chemical microscope has been developed to measure the electric potential distribution of liquid phase lithium ion batteries (LIBs) during charging and discharging. A LIB was fabricated on a sensing plate, which consists of SiO2 and Si films on a sapphire substrate, to generate THz pulses by a laser irradiation. Since the amplitude of THz is proportional to the electric potential on the sensing plate, the electric potential distribution of the lithium ion battery on the sensing plate could be visualized. In this study, the electric potential distribution across a conventional all-solid-state LIB was measured by immobilizing the LIB on the sensing plate using epoxy resin. The distribution of the electric potentials of the battery was clearly visualized by the TCM. This result indicates that the TCM could be one of useful tools for the development high performance batteries.

DOI： 10.1109/IRMMW-THz50927.2022.9896121

Ceria-based solid electrolyte exhibits superior mechanical and electric properties compared to zirconia-based solid electrolyte

Akira Kishimoto, Taiga Umemura, Shinya Kondo, Takashi Teranishi

CERAMICS INTERNATIONAL 48 ( 15 ) 21824 - 21831 2022年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

The mechanical strength and electrical characteristics of 10 mol% gadolinium (Gd)-doped ceria (10GDC) and gadolinium-samarium (Gd-Sm) co-doped ceria ceramics treated by contact reduction were investigated. The observed increased strength of 10GDC was similar to the strength previously reported for ceria with and without Sm doping. X-ray photoelectron spectroscopy revealed that only the surface was reduced in the strengthened material. In addition, the strengthened ceramic displayed improved hardness at low test loads, which suggested the formation of a surface compression layer. The reducing conditions did not affect the electrical conductivity of the 10GDC material. Co-doping with 10 mol% each of Gd and Sm improved strength and conductivity compared with 10GDC and 20GDC. When the co-doped material was reduced, the electric conductivity remained identical; however, the mechanical strength improved, exceeding the strength of zirconia.

DOI： 10.1016/j.ceramint.2022.04.166

Case report of a Japanese patient with chronic renal failure who developed SARS-CoV-2 in a hospital cluster during treatment for acute respiratory failure: An autopsy report

Yoshifumi Amari, Satoshi Morimoto, Takashi Teranishi, Mai Ohata, Atsushi Takeshita, Hiroshi Hirano, Hitoshi Kobayashi

CLINICAL CASE REPORTS 10 ( 7 ) 2022年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

This article reports a clinical and histopathological perspective which noted not only COVID-19 pneumonia but also exacerbation of chronic renal failure potentially caused by thrombus in the kidney, possibly COVID-19-related lesions. The accumulation of autopsy cases will elucidate the pathogenesis of COVID-19 and aid in the development of effective therapeutics.

DOI： 10.1002/ccr3.6024

Capacity retention improvement of LiCoO2 cathodes via their laser-ablation-based nanodecoration by BaTiO3 nanoparticles

Takashi Teranishi, Yumi Yoshikawa, Joel Leblanc-Lavoie, Nazar Delegan, Ibrahima Ka, Akira Kishimoto, My Ali El Khakani

JOURNAL OF APPLIED PHYSICS 131 ( 12 ) 124105 - 124105 2022年3月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

We report on the pulsed-laser-deposition (PLD) based nanodecoration of LiCoO₂ (LCO) with BaTiO₃ (BTO) nanoparticles (NPs) aimed at increasing the density of dielectric-active material–electrolyte triple-phase interfaces (TPIs). The BTO-NPs were deposited onto LCO at different numbers of laser pulses (N_Lp) and two different schemes, namely, (i) BTO-NP deposition on the surface of the precast cathode (“2D-nanodecoration”) and (ii) BTO-NP decoration of LCO powder prior to its processing to form a working cathode (“3D-nanodecoration”). While the “2D-nanodecoration” mode was found to improve significantly the discharge capacity of the LCO cathodes (by ∼30 mAh/g for N_Lp ≥ 200), their capacity retention (CR) was modest. In contrast, the “3D-nanodecoration” scheme enabled not only the volumic nanodecoration of the LCO powder by BTO-NPs but also their subsequent annealing to improve their crystallinity. These 3D-nanodecorated LCO cathodes were found to exhibit significantly higher CR values. In particular, for N_Lp = 100 k, a CR (@10 °C) as high as 78% was achieved (∼47% higher than that of their sol–gel-processed cathode counterparts). Our results point out that three key ingredients (small BTO-NP size, high D_TPI, and high dispersibility of NPs on LCO) should be combined to ensure a high CR of BTO-NP-decorated LCO cathodes.

DOI： 10.1063/5.0075970

Evaluation of superplastic-foamed zirconia-based ceramics using foaming agent and a superplasticity facilitator derived from rice husk

Akira Kishimoto, Kentaro Tanaka, Takashi Teranishi

JOURNAL OF POROUS MATERIALS 29 ( 1 ) 153 - 159 2022年2月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

The applicability of rice husks to solid phase foaming ceramics was assessed. Through an atmospheric heat treatment on silicon carbide based mixture produced by the reduction heat treatment of rice husks, the residual carbon was mostly eliminated, giving a foaming agent composed of approximately SiC and SiO2. Solid-phase foamed porous ceramics was fabricated using this rice husk-derived foaming agent and the properties were compared with that fabricated from commercially available SiC. The sample fabricated from the rice husk-derived foaming agent showed favorable performances in terms of both strength and heat insulating properties. In comparison with the sample fabricated by adding commercially available silica in addition to commercial SiC, the strength became comparable, however, its heat insulating property was still inferior to that using rice husk-derived foaming agent. The increase in mechanical strength can be ascribed to the suppression of the grain growth due to the added silica. The formed silica phase existing at the grain boundaries would affect the thermal conductivity.

DOI： 10.1007/s10934-021-01156-3

その他リンク： https://link.springer.com/article/10.1007/s10934-021-01156-3/fulltext.html

Ultrafast Ion Transport via Dielectric Nanocube Interface

Takashi Teranishi, Ryoji Yamanaka, Ken-ichi Mimura, Mika Yoneda, Shinya Kondo, Kazumi Kato, Akira Kishimoto

ADVANCED MATERIALS INTERFACES 9 ( 4 ) 2022年2月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

Drastic enhancement in the high-rate capability of lithium-ion batteries to the level of supercapacitors while maintaining high energy density is required for next-generation power sources. Incorporating dielectric BaTiO3 (BTO)-based nanocubes (NCs) into the active materials-electrolyte interface provides an ultrafast charge transfer pathway via the dielectric layer. The highly dispersed NC-decorated LiCoO2 (LCO) treated at the optimized temperature of 600 degrees C displays significantly enhanced high-rate capability; the cell maintains 56.7 mAh g(-1) at 50C (1C = 160 mA g(-1)), which compares with null capacity at the same rate for bare LCO. Comparing the NCs with conventional sol-gel-derived nanoparticles, the capacity retention at 10C (vs 0.1C) steadily increases with increasing active materials-dielectric-electrolyte triple-phase interface (TPI) in the NC-decorated case, whereas the capacity retention decreases markedly at similar TPI density in the sol-gel case. In the sol-gel case, the amount of Li ions accumulating at the TPI greatly exceeds the maximum amount of Li ions involved in electron exchange through the redox reaction within the charge/discharge time. In the NC case, most Li ions at the TPI participate effectively in the redox reaction, which results in fast charge transfer since the TPI sites are abundantly supplied with Li ions.

DOI： 10.1002/admi.202101682

Development of impedance measurement of lithium ion batteries electrode using terahertz chemical microscope

Masashi Shimizu, Ryoji Yamanaka, Takashi Teranishi, Jin Wang, Kenji Sakai, Keiji Tsukada, Toshihiko Kiwa

ELECTRICAL ENGINEERING IN JAPAN 214 ( 4 ) 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

In recent years, with the spread of electric vehicles, improvement in the performance of lithium ion batteries has been required. Evaluation of the active material is important because the performance of the lithium ion battery is affected by the movement of lithium ions at the electrode active material-electrolyte interface. In this study, we fabricated a lithium ion battery with the sensing plate, which is a potential sensor, attached to the positive electrode, and evaluated lithium ion battery with a terahertz chemical microscope (TCM). As a result, we succeeded in measuring the potential distribution of the positive electrode during charging and discharging, and the local impedance.

DOI： 10.1002/eej.23355

その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eej.23355

A surface-supporting method for an anode material of Li4Ti5O12 via an epitaxial thin film approach

Sou Yasuhara, Shintaro Yasui, Takashi Teranishi, Takuya Hoshina, Takaaki Tsurumi, Mitsuru Itoh

JAPANESE JOURNAL OF APPLIED PHYSICS 60 ( SF ) 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

High-speed rechargeability is essential for next-generation secondary batteries. Introducing a surface-supporting material deposited on a cathode material accelerates Li-ion motions between an electrode-electrolyte interface by an electric field concentration at a supporting material-cathode-electrolyte (triple-phase) interface (TPI). In addition, a high relative permittivity material was found to be a promising supporting material with which to reinforce the electric field concentration at TPIs. However, the TPI's effects on anode materials remains to be revealed. To demonstrate those effects, we prepared CeO2 or BaTiO3 micropads deposited on Li4Ti5O12 epitaxial thin films. Compared with the cathodes, CeO2 micropads deposited on Li4Ti5O12 film showed the best performance at a high C-rate. Because the rate-determining step of Li4Ti5O12 epitaxial thin films is inner diffusion, reinforcing the surface electric field by the deposition of a low relative permittivity materials could promote high C-rate performance even in anode materials.

DOI： 10.35848/1347-4065/ac15a8

Influence of orientation on the electro-optic effect in epitaxial Y-doped HfO2 ferroelectric thin films

Shinya Kondo, Reijiro Shimura, Takashi Teranishi, Akira Kishimoto, Takanori Nagasaki, Hiroshi Funakubo, Tomoaki Yamada

JAPANESE JOURNAL OF APPLIED PHYSICS 60 ( SF ) 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

Recently, we reported linear electro-optic (EO) effects in (100)-epitaxial yttrium-doped hafnium dioxide (Y-HfO2) ferroelectric thin films. In this study, we have investigated the influence of orientation on the EO effect in Y-HfO2 thin-film. (111)-epitaxial undoped HfO2 and Y-HfO2 films were deposited on Sn-doped In2O3/yttria-stabilized zirconia (111) substrates at room temperature through radiofrequency magnetron sputtering. Although the undoped HfO2 film showed typical paraelectric characteristics, ferroelectricity was observed in the (111)-Y-HfO2 film. Remnant polarization in the (111)-Y-HfO2 film was higher than that in the (100)-Y-HfO2 film. The (111)-Y-HfO2 film exhibited a linear EO effect based on ferroelectricity, which is consistent with that of the (100)-Y-HfO2 film. The average EO coefficient r (c) of the (111)-Y-HfO2 film was 0.67 pm V-1, which is higher than that of the (100)-Y-HfO2 film. This result is reasonable considering the difference in remnant polarization between the (100)-Y-HfO2 and (111)-Y-HfO2 films.

DOI： 10.35848/1347-4065/ac17e0

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ac17e0/pdf

Revealing intrinsic electro-optic effect in single domain Pb(Zr, Ti)O-3 thin films

Shinya Kondo, Tomoaki Yamada, Masahito Yoshino, Takashi Teranishi, Akira Kishimoto, Takanori Nagasaki

APPLIED PHYSICS LETTERS 119 ( 10 ) 102902 - 102902 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

We deposited polar-axis-oriented tetragonal and rhombohedral single domain Pb(Zr, Ti)O-3 (PZT) films on CaF2(100) substrates by inserting SrRuO3 (SRO)/LaNiO3 and SRO/SrTiO3/TiO2/CeO2 buffer layers. Both PZT films grew epitaxially and had a (001)- and (111)-domain with the remnant polarization and piezoelectric constant comparable to the theoretical values of PZT single crystals having the same compositions. The electro-optic (EO) response of the fabricated PZT films was constant with respect to the DC electric field and increased linearly with an increasing AC electric field, thus representing a typical linear EO response in single domain ferroelectrics. The measured EO coefficients were larger than the value for a single crystal of PbTiO3, i.e., one of the end members of PZT, but smaller than the values reported for polycrystalline and epitaxial PZT films with multiple domains. These findings show that the intrinsic EO effect is enhanced in PZT, which is similar to the enhancement seen in the dielectric and piezoelectric constants. Moreover, most of the reported EO response in PZT films is supported by additional extrinsic contributions.

DOI： 10.1063/5.0056121

Development of impedance measurement of lithium ion batteries electrode using terahertz chemical microscope

Masashi Shimizu, Ryoji Yamanaka, Takashi Teranishi, Jin Wang, Kenji Sakai, Keiji Tsukada, Toshihiko Kiwa

IEEJ Transactions on Sensors and Micromachines 141 ( 8 ) 273 - 278 2021年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electrical Engineers of Japan

In recent years, with the spread of electric vehicles, improvement in the performance of lithium ion batteries has been required. Evaluation of the active material is important because the performance of the lithium ion battery is affected by the movement of lithium ions at the electrode active material-electrolyte interface. In this study, we fabricated a lithium ion battery with the sensing plate, which is a potential sensor, attached to the positive electrode, and evaluated lithium ion battery with a Terahertz Chemical Microscope. As a result, we succeeded in measuring the potential distribution of the positive electrode during charging and discharging, and the local impedance.

DOI： 10.1541/ieejsmas.141.273

Linear electro-optic effect in ferroelectric HfO2-based epitaxial thin films

Shinya Kondo, Reijiro Shimura, Takashi Teranishi, Akira Kishimoto, Takanori Nagasaki, Hiroshi Funakubo, Tomoaki Yamada

JAPANESE JOURNAL OF APPLIED PHYSICS 60 ( 7 ) 070905 - 070905 2021年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

<title>Abstract</title>
Electro-optic (EO) modulators for silicon photonics using CMOS-compatible materials and processes are in great demand. In this study, epitaxial (100)-undoped HfO₂ and Y-doped HfO₂ thin films were fabricated on Sn-doped In₂O₃/yttria-stabilized zirconia(100) substrates at room temperature via magnetron sputtering. EO measurement of the Y-HfO₂ film using modulation ellipsometry showed that the phase was changed by 180° after application of positive and negative poling biases, and the modulation amplitude increased linearly with increasing AC electric field, indicating a linear EO effect based on ferroelectricity. The observed results indicate that ferroelectric HfO₂-based films are viable candidates for CMOS-compatible EO devices.

DOI： 10.35848/1347-4065/ac087d

その他リンク： https://iopscience.iop.org/article/10.35848/1347-4065/ac087d/pdf

Suppression Mechanisms of the Solid-Electrolyte Interface Formation at the Triple-Phase Interfaces in Thin-Film Li-Ion Batteries

Sou Yasuhara, Shintaro Yasui, Takashi Teranishi, Osami Sakata, Takuya Hoshina, Takaaki Tsurumi, Yutaka Majima, Mitsuru Itoh

ACS APPLIED MATERIALS & INTERFACES 13 ( 29 ) 34027 - 34032 2021年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Side reactions of the charge/discharge in Li-ion batteries (LIBs) generate a solid-electrolyte interface (SEI) onto an electrode surface, resulting in the degradation of the lifetime of a cell. The suppression of SEI formations has attracted much attention for achieving longer cyclable LIBs. Our research group has previously reported that few SEI were observed at triple-phase interfaces (TPIs) consisting of BaTiO3, LiCoO2, and electrolyte interfaces in LIBs with excellent cyclability and ultrahigh-speed chargeability. An investigation on the suppression mechanisms of SEI formations at TPIs should yield important information on understanding the undesirable side reactions. Therefore, we have explored the suppression mechanisms of SEI formations by preparing epitaxial thin films and evaluating the surface of the samples after the electrochemical treatment. The results of X-ray photoelectron spectroscopy and scanning electron microscopy with energy-dispersive X-ray analysis measurements suggested that the decomposition of LiPF6 was suppressed at TPIs, implying that the generation of PF5 via the decomposition of LiPF6 contributed to SEI formation.

DOI： 10.1021/acsami.1c05090

Surface-supporting method of micropad deposition onto LiCoO2 epitaxial thin films to improve high C-rate performance

Sou Yasuhara, Shintaro Yasui, Takashi Teranishi, Takuya Hoshina, Takaaki Tsurumi, Mitsuru Itoh

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 129 ( 7 ) 415 - 418 2021年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

High-speed rechargeable Li ion batteries are in strong demand. Two methods have been reported to improve the high-speed rechargeability of electrodes: reducing particle size and introducing a surface support. However, the effectiveness of the latter could not be directly compared among reports due particle size differences from study to study. Our previous report revealed that Li+ motion under high-speed charge-discharge conditions is accelerated around a surface-supporting material, an electrode, and an electrolyte interface. In this study, we prepared epitaxial LiCoO2 thin films with micropads of various kinds of materials and evaluated the high-speed rechargeability of each. (C) 2021 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.20237

Ultrafast charge transfer at the electrode electrolyte interface via an artificial dielectric layer

Takashi Teranishi, Kaisei Kozai, Sou Yasuhara, Shintaro Yasui, Naoyuki Ishida, Kunihiro Ishida, Masanobu Nakayama, Akira Kishimoto

JOURNAL OF POWER SOURCES 494 2021年5月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER

We report ultrafast charge transfer along the Li-ion pathway via a dielectric layer at the electrolyte electrode interface. The rate capabilities of dielectric-modified cathodes were evaluated as a function of the combination of electrolyte solvents and dielectric layers having various dielectric constants, epsilon(r). The high-rate capability was enhanced when the loaded dielectric layer's epsilon(r) was close to that of the electrolyte solvent. Density functional theory molecular dynamics calculations and atomic force microscope force measurements confirmed that the activation energies related to Li+ adsorption and desolvation were notably reduced when the loaded dielectric layer's epsilon(r) approached that of the solvent. In this case, the solvated Li+ ion preferentially underwent desolvation on the solid surface. The discharge capacity at the ultrahigh rate of 50 C (1 C = 160 mA g(-1)) of the dielectric-modified thin films steadily increased with increasing length of the dielectrics electrode electrolyte triple-phase interface (TPI). Experimental and computational results reveal that, when the permittivity of the dielectrics and solvent are similar, solvated Li+ ions are preferentially involved in the physical adsorption and desolvation on the dielectric surface, followed by Li+ intercalation near the TPI.

DOI： 10.1016/j.jpowsour.2021.229710

Controlled colossal polarization originating in the Li-ion conductor-dielectric interface

Takashi Teranishi, Yuki Nishikori, Mika Yoneda, Akira Kishimoto

JAPANESE JOURNAL OF APPLIED PHYSICS 60 ( 4 ) 2021年4月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

A novel colossal polarization architecture generated at the fast Li-ion conductor-dielectric interface is proposed. A fast Li-ion conductor, La0.57Li0.29TiO3 (LLT), is utilized as the conductive core material, while the ferroelectric barium titanate (BaTiO3; BT) was coated onto the LLT as the shell layer via a liquid phase reaction. After densification of the composites, the shell BT fully transforms into the interdiffusion layer, i.e. (Ba, Li, La)TiO3 (BLLT). The BLLT effectively hinders Li diffusion, leading to a colossal polarization at the core-shell interface. Consequently, the optimized BT-LLT achieves dielectric characteristics at 1 kHz with permittivity of 3.28 x 10(4).

DOI： 10.35848/1347-4065/abf088

Investigation of Cross-Section Measurement Method for All-Solid-State Batteries Using Terahertz Chemical Microscopy

Masashi Shimizu, Ryota Tomie, Kashu Hamada, Takashi Teranishi, Jin Wang, Kenji Sakai, Toshihiko Kiwa

2021 46TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ) 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In recent years, all-solid-state batteries have been attracting attention as secondary batteries to replace Li ion batteries. To improve the performance of all-solid-state batteries, measurement methods are required to evaluate electrode-solid electrolyte interfaces and electrochemical reactions between electrodes. In this study, we investigated a measurement method for the cross-section of all-solid-state batteries using terahertz chemical microscopy (TCM). We fabricated a model of all-solid-state battery and showed the possibility of using TCM to measure the cross-section of the all-solid-state battery by measuring the cross-section of a model of all-solid-state battery.

DOI： 10.1109/IRMMW-THz50926.2021.9567015

Electric Potential Distribution on Lithium Ion Battery Cathodes Measured Using Terahertz Chemical Microscopy 査読

Toshihiko Kiwa, Yuki Akiwa, Hayato Fujita, Takashi Teranishi, Kenji Sakai, Hidetoshi Nose, Masaki Kobayashi, Keiji Tsukada

JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES 41 ( 4 ) 430 - 437 2020年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

A terahertz chemical microscope has been developed to visualize electric potential distribution on lithium ion battery cathodes during battery operation. A sensing plate comprising a Si film grown epitaxially on a sapphire substrate was used as a terahertz emitter. The amplitude of terahertz radiation from the sensing plate could be related to the electric potential at the exact point where a femtosecond laser illuminated. Here, the sensing plate was integrated into a conventional can-type lithium ion battery and terahertz radiation from the sensing plate was observed during battery operation between 2.7 and 4.2 V. By scanning the laser, the distribution of terahertz amplitude radiated from the sensing plate was observed, which could be related to the electric potential distribution on the electrodes of the batteries. Localized electric potential could be visualized as the amplitude of terahertz radiation generated in the sensing plate, which was integrated beneath the battery electrode.

DOI： 10.1007/s10762-019-00640-x

Influence of Reduction Annealing on the Characteristics of CeO<sub>2</sub> – YSZ Based Oxide Ceramics

Taiga UMEMURA, Takashi TERANISHI, Akira KISHIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy 67 ( 3 ) 163 - 166 2020年3月

High-frequency dielectric characterization of electronic defect states in co-sputtered W-doped TiO2

N. Delegan, T. Teranishi, M. A. El Khakani

Journal of Applied Physics 125 ( 20 ) 205103 - 205103 2019年5月

Enhancement of Ultrahigh Rate Chargeability by Interfacial Nanodot BaTiO₃ Treatment on LiCoO₂ Cathode Thin Film Batteries

Sou Yasuhara, Shintaro Yasui, Takashi Teranishi, Keisuke Chajima, Yumi Yoshikawa, Yutaka Majima, Tomoyasu Taniyama, Mitsuru Itoh

Nano Letters 19 ( 3 ) 1688 - 1694 2019年2月

Utilizing Rice Husk for Ceramic and Glass Foams as Matrix and Foaming Agent

Chiaki MATSUOKA, Takashi TERANISHI, Hidetaka HAYASHI, Akira KISHIMOTO

Journal of the Japan Society of Powder and Powder Metallurgy 65 ( 8 ) 475 - 480 2018年8月

Aluminum Interdiffusion into LiCoO2 Using Atomic Layer Deposition for High Rate Lithium Ion Batteries 査読

T. Teranishi, Y. Yoshikawa, M. Yoneda, A. Kishimoto, J. Halpin, S. O’Brien, M. Modreanu, I. M. Povey

ACS Appl. Energy Mater. 1 3277 - 3282 2018年6月

Low-temperature High-rate Capabilities of Lithium Batteries via Polarization-assisted Ion Pathways 査読

T. Teranishi, N. Katsuji, K. Chajima, S. Yasuhara, M. Inohara, Y. Yoshikawa, S. Yasui, H. Hayashi, A. Kishimoto, M. Itoh

Advanced Electronic Materials 4 1700413 2018年3月

Domain engineering enhanced microwave tunability in nonstoichiometric Ba0.8Sr0.2TiO3 査読

T. Teranishi, K. Osaki, H. Hayashi, A. Kishimoto

J. Am. Ceram. Soc. 101 ( 2 ) 723 - 731 2018年2月

Millimeter-wave irradiation heating for operation of doped CeO2 electrolyte-supported single solid oxide fuel cell 査読

Salmie S. C. Abdullah, T. Teranishi, H. Hayashi and A. Kishimoto

Journal of Power Sources 374 92 - 96 2018年1月

Synthesis of nano-crystalline LiNbO3-decorated LiCoO2 and resulting highrate capabilities", Solid State Ionics 査読

T. Teranishi, M. Inohara, J. Kano, H. Hayashi, A. Kishimoto, K. Yoda, H. Motobayashi, Y. Tasaki

Solid State Ionics 314 57 - 60 2018年1月

Millimeter-wave irradiation heating for operation of doped CeO 2 electrolyte-supported single solid oxide fuel cell 査読

Salmie Suhana Binti Che Abdullah, Takashi Teranishi, Hidetaka Hayashi, Akira Kishimoto

Journal of Power Sources 374 92 - 96 2018年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier BV

High operation temperature of solid oxide fuel cell (SOFC) results in high cell and operation cost, time consuming and fast cell degradation. Developing high performance SOFC that operates at lower temperature is required. Here we demonstrate 24 GHz microwave as a rapid heating source to replace conventional heating method for SOFC operation using 20 mol% Sm doped CeO2 electrolyte-supported single cell. The tested cell shows improvement of 62% in maximum power density at 630 °C under microwave heating. This improvement governs by bulk conductivity of the electrolyte. Investigation of ionic transference number reveals that the value is unchanged under microwave irradiation, confirming the charge carrier is dominated by oxygen ion species. This work shows a potential new concept of high performance as well as cost and energy effective SOFC.

DOI： 10.1016/j.jpowsour.2017.11.036

LaGaO<sub>3</sub>系セラミックスにおける酸化物イオン伝導に及ぼすミリ波照射加熱の影響査読

工藤侑芽、藤井祐里、蓮沼英樹、寺西貴志、林秀考、岸本昭

粉体および粉末冶金 65 ( 1 ) 21 - 25 2018年

Evaluation of Li-ion battery using a Terahertz Chemical Microscope

Yuki Akiwa, Kentarou Fujiwara, Yumi Yoshikawa, Takashi Teranishi, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) 2018年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

We measured the terahertz wave intensity of the active material surface using TCM as a method to evaluate lithium ion batteries. We made a battery with a sensing plate attached to measure with TCM. As a result, changes in the terahertz wave intensity due to charging and discharging of the battery could be measured. This result indicates that the extraction and insertion of lithium in the active material can be measured by TCM in the future.

Relationship between thermal environment and conductivity enhancement under millimeter-wave irradiation heating of zirconia ceramics 査読

KISHIMOTO Akira, SHIMOYAMA Koyo, TERANISHI Takashi, HAYASHI Hidetaka

Journal of the Ceramic Society of Japan 125 ( 10 ) 717 - 720 2017年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人日本セラミックス協会

Improving the conductivity of 8 mol % yttria-stabilized zirconia (8YSZ) electrolyte has enabled a lowering of the operating temperature of solid oxide fuel cells. We previously reported that millimeter-wave irradiation heating increases the ionic conductivity of ceramics. The ionic conductivity of 8YSZ under millimeter-wave irradiation heating had been up to 20 times higher than that with conventional heating. In the present study, we investigated the optimal thermal environment for millimeter-wave irradiation heating. We also investigated the thermal profile of samples under millimeter-wave irradiation heating to elucidate the rate of the non-thermal effect.

DOI： 10.2109/jcersj2.17056

Loading effect of a barium titanate artificial interface on high voltage capabilities at high charge and discharge rates 査読

Yoshikawa Yumi, Teranishi Takashi, Hayashi Hidetaka, Kishimoto Akira

Jpn. J. Appl. Phys. 56 ( 10 ) 10PC01 - 4959 2017年9月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Physics

Cyclic characteristics of BaTiO<inf>3</inf>(BT)-decorated LiCoO<inf>2</inf>(LC), for use as an artificial solid electrolyte interface (SEI) were evaluated at high voltages. Within the standard voltage window (i.e., 3.3–4.2 V), the BT-decorated LC exhibited greater capacities for up to 80 cycles compared with both the Al<inf>2</inf>O<inf>3</inf>(paraelectric)-decorated and bare LC SEIs. The discharge capacity retention after 80 cycles (compared with the initial value) was 86.0% for the BT–LC cathode. This is a significant improvement over both the bare LC that showed 19.9% retention and the Al<inf>2</inf>O<inf>3</inf>–LC that displayed 71.5% retention. Thereafter, the cyclic stabilities of the BT–LC and bare LC were compared within potential windows at cutoff voltages as high as 4.9 V. In this region, BT decoration yielded marked improvements in capacity retention after 50 cycles, up to a potential of 4.7 V. The post-situ XRD analysis of the cathode sheets showed that BT decoration effectively stabilized the hexagonal crystal structure of the LC, H1, resulting in the said cyclic stability increase. These observations demonstrate that the use of BT in SEI allows a significant increase in working voltage while maintaining the chemical stability of the underlying LC matrix, a key advancement in the perpetual pursuit of ever higher cell energy densities.

DOI： 10.7567/JJAP.56.10PC01

Broadband spectroscopy of dielectrics and oxygen-ion conductors 査読

Takashi Teranishi *

Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan, Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan, Journal of the Ceramic Society of Japan 125 ( 7 ) 547 - 551 2017年7月

Electrodeposition of Ni-Al（OH）₃ Composite Films from NO₃^－ Containing Non-Suspended Bath

Toru ASANO, Hidetaka HAYASHI, Takashi TERANISHI, Akira KISHIMOTO, Kazuya ISHII

Journal of The Surface Finishing Society of Japan 68 ( 7 ) 401 - 404 2017年7月

Polarization behavior of sol-gel-derived relaxor Ba(Zr, Ti)O3 films 査読

Takashi Teranishi *,Shin Kajiyama,Hidetaka Hayashi*,Akira Kishimoto*

Journal of the American Ceramic Society 100 ( 4 ) 1542 - 1550 2017年4月

Effect of the (Ba + Sr)/Ti ratio on the microwave-tunable properties of Ba0.6Sr0.4TiO3 ceramics 査読

Takashi Teranishi *,Riku Kanemoto,Hidetaka Hayashi*,Akira Kishimoto*

Journal of the American Ceramic Society 100 ( 3 ) 1037 - 1043 2017年3月

Enhanced electrical conductivity of doped CeO2 under millimeter-wave irradiation heating 査読

Salmie Suhana Binti Che Abdullah,Takashi Teranishi *,Hidetaka Hayashi*,Akira Kishimoto*

Materials and Design, International Journal of Materials in Engineering Applications 115 231 - 237 2017年2月

固相発泡により扁平気孔を導入した高温圧力センサーの特性向上 (特集粉末冶金プロセスによる製造技術とその材料評価の新展開) 査読

高室佑基, 寺西貴志, 林秀考, 岸本昭

粉体および粉末冶金 = Journal of the Japan Society of Powder and Powder Metallurgy : 紛体粉末冶金協会誌 64 ( 2 ) 68 - 72 2017年2月

Gastight, closed pore inclusive porous ceramics through a superplastically foaming method 査読

A. Kishimoto, A. Tohji, T. Teranishi and H. Hayashi

Ceram. Trans 2016年10月

Quantitative study of band structure in BaTiO3 particles with vacant ionic sites 査読

Norihiro Oshime,Jun Kano*,Naoshi Ikeda*,Takashi Teranishi*,Tatsuo Fujii*,Takeji Ueda,Tomoko Ohkubo

Journal of Applied Physics 120 ( 15 ) 2016年10月

High rate capability of a BaTiO3-decorated LiCoO2 cathode prepared via metal organic decomposition 査読

Takashi Teranishi*,Naoto Katsuji,Yumi Yoshikawa,Mika Yoneda,Hidetaka Hayashi*,Akira Kishimoto*,Koji Yoda,Hidefumi Motobayashi,Yuzo Tasaki

Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, Japanese Journal of Applied Physics, Japanese Journal of Applied Physics, Part 2: Letters 55 ( 10 ) 2016年10月

Influence of PMSA-based polymer on the settling velocity of CNT in Aqueous Media 査読

Naoyuki Nishimura, Shin-Ichi Takeda, Takashi Teranishi, Hidetaka Hayashi, Naoto Saito, Akira Kishimoto

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 63 ( 10 ) 861 - 865 2016年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the Japan Society of Powder and Powder Metallurgy

The preparation of a stable suspension dispersing carbon nanotube (CNT) in aqueous media using polystyrene maleic acid (PSMA)-based polymer as surfactant was attempted to be subsequently used in the fabrication of high-performance ceramic matrix composites. Settling velocity under centrifugation analysis was experimentally evaluated as one of the stability criteria of the dispersion and pulsed nuclear magnetic resonance was used to evaluate the amount of adsorbed molecules. The settling velocity decreased considerably with the PSMA concentration up to the saturation at around 7 mass%, then further decreased gradually with PSMA. The former was thought to be based on the dissociation of CNT agglomerate and the latter would be attributed to the surfactant-induced network structure formed in the aqueous media.

DOI： 10.2497/jjspm.63.861

Gastight, closed pore inclusive porous ceramics through a superplastically foaming method 査読

Akira Kishimoto, Atsuki Tohji, Takashi Teranishi, Hidetaka Hayashi

Ceramic for Environmental Systems 257 69 - 79 2016年5月

記述言語：英語掲載種別：論文集(書籍)内論文出版者・発行元：Wiley Blackwell

Our innovative superplastically foaming method was used to create closed-pore inclusive zirconia-based ceramics. Yttrium oxide was added to monoclinic zirconia to stabilize the matrix. Sintering and superplastic deformation were used to form a solid solution and transform it to a cubic phase. Porous ceramics formed via this post-stabilization method exhibited anomalous thermal expansion due to the silica derived from the foaming agent SiC. This anomalous thermal expansion disappeared following substitution of the SiC foaming agent for AlN. The resulting superplastically foamed porous ceramics exhibited large thermal conductivities, comparable to that of the fully densified ceramics, but with a porosity as great as 35%. This high thermal conductivity was attributed to the alumina derived from the foaming agent AlN. To suppress the formation of alumina, the samples were pre-sintered in an argon atmosphere. The modified superplastically foamed ceramics exhibited smaller pores, with a porosity of 33%, as well as favorable thermal insulation, with a thermal conductivity that was approximately half that of the fully dense material.

DOI： 10.1002/9781119234463.ch7

Electrical Conductivity of Ceria-based Oxide under 24 GHz Millimeter-wave Heating in Varying Thermal Environments 査読

CHE ABDULLAH Salmie Suhana Binti, TERANISHI Takashi, HAYASHI Hidetaka, KISHIMOTO Akira

粉体および粉末冶金 63 ( 7 ) 663 - 667 2016年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人粉体粉末冶金協会

<p>Sm-doped CeO₂ ceramics were prepared by conventional solid state method. The electrical conductivity of the samples was measured under conventional heating and 24 GHz millimeter-wave (MMW) heating, and the results were compared. During MMW heating, 5 mol% Sm-doped CeO₂ pellets with different thickness were used as susceptors, meanwhile Al₂O₃ fiber board was used as thermal insulator and its design varies by the number of open channels. The aforementioned susceptors and thermal insulators dependency of conductivity values during MMW heating were studied. Conductivity of samples under MMW heating was found to be higher than under conventional heating. Results showed that the different susceptor thickness and thermal insulator design could result in different conductivity values. These results were attributed to the phenomenon of heat dissipation from surface and the amount of direct radiation reached the sample. Specific susceptor thickness and specific insulator design which leads to highest conductivity were identified. By combining these two effects, the largest enhancement of conductivity of ceria based ceramics was obtained.</p>

DOI： 10.2497/jjspm.63.663

Lithium ion conductivity of oriented Li0.33La0.56TiO3 solid electrolyte films prepared by a sol-gel process 査読

Takashi Teranishi*,Yuki Ishii,Hidetaka Hayashi*,Akira Kishimoto*

Solid State Ionics, Reactivity of Solids 284 1 - 6 2016年1月

セリア/ジルコニアセラミックス対のカチオン相互拡散に及ぼすミリ波照射の影響査読

脇本幹也、寺西貴志、林秀考、岸本昭

粉体および粉末冶金 63 ( 11 ) 981 - 985 2016年

In situ time-resolved dispersive X-ray absorption fine structure analysis of BaTiO3-LiCoO2 composites for lithium ion batteries 査読

Takashi Teranishi*,Yumi Yoshikawa,Ryota Miyahara,Hidetaka Hayashi*,Akira Kishimoto*,Misaki Katayama,Yasuhiro Inada

Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan, Yogyo Kyokai Shi/Journal of the Ceramic Society of Japan 124 ( 6 ) 659 - 663 2016年

21aAF-3 BaTiO_3のバンド構造におけるイオン欠損効果

押目典宏, 狩野旬, 池田直, 寺西貴志, 大崎浩司, 藤井達生, 上田剛慈, 大久保智子

日本物理学会講演概要集 71 2691 - 2691 2016年

Stabilisation dopant-dependent facilitation in ionic conductivity on millimeter-wave irradiation heating of zirconia-based ceramics 査読

Akira Kishimoto, Hideki Hasunuma, Takashi Teranishi, Hidetaka Hayashi

JOURNAL OF ALLOYS AND COMPOUNDS 648 740 - 744 2015年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE SA

Ionic conductivity was measured on scandia-, calcia-, and gadolinia-stabilised zirconia ceramics under quasi-millimeter-wave (MMW) irradiation heating and conventional heating. Conductivity enhancement was evaluated for these ceramics and compared with our previous report on yttria- and ytterbia-stabilised zirconia ceramics (YSZ and YbSZ, respectively). The ionic conduction for the various cation-substituted zirconia ceramics was enhanced under MMW irradiation heating. In the case of scandia-stabilisation, the optimal composition demonstrating maximum ionic conductivity was 12-mol% zirconia (ScSZ) under MMW irradiation heating, which was larger than under conventional heating. Such an optimal composition shift was similar to results for YSZ ceramics. These results are discussed in terms of the activation energies for vacancy-ion dissociation and ion transfer. (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jallcom.2015.07.057

High-Rate Capabilities of Ferroelectric BaTiO3?LiCoO2 Composites with Optimized BaTiO3 Loading for Li-Ion Batteries 査読

T. Teranishi, Y. Yoshikawa, R. Sakuma, H. Okamura, H. Hashimoto, H. Hayashi, T. Fujii, A. Kishimoto, and Y. Takeda

ECS Electrochemistry Letters 4 A137 2015年10月

In situ impedance analysis on BaTiO3-LiCoO2 composite cathodes for lithium ion batteries 査読

Takashi Teranishi, Yumi Yoshikawa, Ryo Sakuma, Hirokazu Okamura, Hidetaka Hayashi, Akira Kishimoto, Yasuo Takeda

JAPANESE JOURNAL OF APPLIED PHYSICS 54 ( 10 ) 2015年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

In situ electrochemical impedance spectroscopy (EIS) was undertaken to investigate the contribution of a ferroelectric artificial solid electrolyte interface (SEI) to the enhancement of the rate capability of lithium ion batteries. Resistance elements, consisting of the cell reactions, the resistance of the electrolyte, R-sol, that of the Li metal anode reaction, R-Li, and the charge transfer resistance, R-ct, were measured. A small ferroelectric BaTiO3 (BT) load, similar to 1 mol %, notably reduced R-ct and R-sol compared with bare LiCoO2 (LC), indicating that loaded ferroelectric BT SEIs effectively promote Li inter/deintercalation into and from the active material, LC, and restrict cobalt ion dissolution into the electrolyte liquid. Lower R-ct and R-sol resulted in a significantly higher capacity retention ratio at a 10C rate compared with the initial cycle for small BT load, similar to 1 mol %. The capacity retention dropped rapidly, accompanied by a slight increase in R-ct for larger BT loads, 5 and 15 mol %, which may be attributed to the thicker BT layer and the existence of the impurity phase, BaCO3. These results imply that the ferroelectric SEI affected the kinetics of mobile Li ions at the cathode-electrolyte interface, significantly enhancing the rate capability. (C) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.10NB02

In situ impedance analysis on BaTiO3?LiCoO2 composite cathodes for lithium ion batteries 査読

T. Teranishi, Y. Yoshikawa, R. Sakuma, H. Okamura, H. Hayashi, A. Kishimoto, and Y. Takeda

Japanese Journal of Applied Physics 54 10NB02 2015年9月

Influence of PMSA-based polymer on the settling velocity of CNT in Aqueous Media 査読

Naoyuki Nishimura,Shin Ichi Takeda,Takashi Teranishi*,Hidetaka Hayashi*,Naoto Saito,Akira Kishimoto*

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy, journal of the japan society of powder and powder metallurgy, Journal of the Japan Society of Powder and Powder Metallurgy 63 ( 10 ) 861 - 865 2015年9月

Effect of 24 GHz microwave heating on creep deformation of yttria partially stabilised zirconia ceramics with titania and tin oxide additives 査読

Akira Kishimoto, Kyohei Yamashita, Takashi Teranishi, Hidetaka Hayashi, Saburo Sano

CERAMICS INTERNATIONAL 41 ( 4 ) 5785 - 5789 2015年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

The effect of quasi-millimetre-wave (24 GHz microwave) heating on creep deformation was investigated on partially-stabilised zirconia through tensile testing at temperatures from 1100 to 1350 degrees C over stresses from 5 to 10 MPa. The specimens were fabricated by sintering the 3 mol% of yttria stabilised ZrO2 (3YSZ) powder dispersed with SiO2, SiO2/SnO2 or SiO2/TiO2 at 1600 degrees C. In tensile test using the quasi-millimetre wave heating, strain rates of SiO2 dispersed 3YSZ were similar to that with a conventional furnace heating. The 3YSZ sample containing the TiO2 addition exhibited a different strain rate when heated by millimeter-wave irradiation as against conventional furnace heating, it is proposed that this difference can be explained due to TiO2 having a high-dielectric constant resulting in a non-thermal effect when subjected to quasi-millimeter wavelength radiation. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

DOI： 10.1016/j.ceramint.2015.01.006

Effect of 24GHz microwave heating on creep deformation of yttria partially stabilised zirconia ceramics with titania and tin oxide additives 査読

A. Kishimoto, K. Yamashita, T. Teranishi, H. Hayashi and S. Sano

Ceramics International 41 5785 2015年4月

Stabilisation dopant-dependent facilitation in ionic conductivity on millimetre-wave irradiation heating of zirconia-based ceramics 査読

A. Kishimoto, H. Hasunuma, T. Teranishi and H. Hayashi

Journal of Alloys and Compounds 648 740 2015年4月

Effect of Mg loading on the high-frequency tunability of Ba0.8Sr0.2TiO3 ceramics 査読

T. Teranishi, T. Sogabe, H. Hayashi, A. Kishimoto, K. Iokibe, and Y. Toyota,

Japanese Journal of Applied Physics 54 011502 2015年4月

High-Rate Capabilities of Ferroelectric BaTiO3-LiCoO2 Composites with Optimized BaTiO3 Loading for Li-Ion Batteries 査読

Takashi Teranishi, Yumi Yoshikawa, Ryo Sakuma, Hirokazu Okamura, Hideki Hashimoto, Hidetaka Hayashi, Tatsuo Fujii, Akira Kishimoto, Yasuo Takeda

ECS ELECTROCHEMISTRY LETTERS 4 ( 12 ) A137 - A140 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELECTROCHEMICAL SOC INC

Ferroelectric barium titanate, BaTiO3 (BT) was coated on lithium cobaltate, LiCoO2 (LC), as an artificial solid electrolyte interface (SEI), via the simple sol-gel route. The high charge-discharge rate capabilities of the composite cathodes were evaluated up to 10C. The LC loaded with 1 mol% of BT had a measured capacity of 146 mAh/g, which was the highest value measured at 10C. This capacity was 78% of its initial value, and was 238% of the capacity of bare LC over the same number of cycles. (C) 2015 The Electrochemical Society. All rights reserved.

DOI： 10.1149/2.0041512eel

22pCH-13 金属-強誘電体接合系での触媒作用

狩野旬, 池田直, 押目典宏, 藤井達生, 橋本英樹, 寺西貴志, 大久保智子, 上田剛慈, 吉田右, 秋山雄介

日本物理学会講演概要集 70 2743 - 2743 2015年

21pCJ-7 Ba_<0.8>Sr_<0.2>TiO_3のMgドープ効果

押目典宏, 狩野旬, 大崎浩司, 寺西貴志, 吉田右, 池田直, 藤井達生, 大久保智子, 上田剛慈

日本物理学会講演概要集 70 2704 - 2704 2015年

High-rate performance of ferroelectric BaTiO3-coated LiCoO2 for Li-ion batteries 査読

T. Teranishi, Y. Yoshikawa, R. Sakuma, H. Hashimoto, H. Hayashi, A. Kishimoto, and T. Fujii

Applied Physics Letters 105 143904 2014年10月

Dependence of the conductivity of polycrystalline Li0.33BaxLa0.56-2/3xTiO3 on Ba loading 査読

Takashi Teranishi, Akane Kouchi, Hidetaka Hayashi, Akira Kishimoto

SOLID STATE IONICS 263 33 - 38 2014年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The dependence of lithium ion conductivity on barium loading was investigated for Li0.33BaxLa0.56-2/3xTiO3 (LBLT, 0 <= x <= 0.1) ceramics. The highest bulk conductivity, sigma(dc), of 1.24 x 10(-3) S cm(-1) obtained for 0.25 mol.% Ba loading was slightly improved compared to that of non-doped Li0.33La0.56TiO3 (1.18 x 10(-3) S cm(-1)). The intensities of the XRD patterns in the independent cubic and tetragonal reflections, i.e., I-c(100) and I-t(101), were analyzed; a larger I-c(100)/I-t(101) ratio corresponded to a larger sigma(dc). A possible reason for the only slight enhancement of the sigma(dc) by a small loading of Ba is an increased volume fraction of the more highly conductive LBLT cubic phase. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2014.05.001

High-rate performance of ferroelectric BaTiO3-coated LiCoO2 for Li-ion batteries 査読

Takashi Teranishi, Yumi Yoshikawa, Ryo Sakuma, Hideki Hashimoto, Hidetaka Hayashi, Akira Kishimoto, Tatsuo Fujii

APPLIED PHYSICS LETTERS 105 ( 14 ) 2014年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER INST PHYSICS

The high charge-discharge rate characteristics of composite cathodes consisting of ferroelectric BaTiO3 (BT)-coated LiCoO2 (LC), synthesized via a simple sol-gel route, were evaluated, and the rate showed stepwise increases to as high as 5C. The LC-BT composite cathode annealed at 600 degrees C, LC-BT-600, notably retained high capacities, i.e., 122 mAh/g at 30 cycles, 5C and 99 mAh/g at 60 cycles, 5C. These capacities corresponded to 83% and 67% of the initial values and were as high as 158% and 245% of the capacities of bare LC over the same cycles, respectively. The ferroelectricity of the coated BT contributed to the improvement in high-rate performance. (c) 2014 AIP Publishing LLC.

DOI： 10.1063/1.4898006

Dependence of the conductivity of polycrystalline Li0.33BaxLa0.56?2/3xTiO3 on Ba loading 査読

T. Teranishi, A. Kouchi, H. Hayashi, and A. Kishimoto

Solid State Ionics 263 33 2014年5月

The isothermal conductivity improvement in zirconia-based ceramics under 24 GHz microwave heating 査読

A. Kishimoto, K. Ayano, T. Teranishi, and H. Hayashi

The isothermal conductivity improvement in zirconia-based ceramics under 24 GHz microwave heating. 143 486 - 489 2014年4月

Relationship Between Phonon Parameters and Oxygen Ion Conductivity for Al?Yb Co-doped Zirconia 査読

T. Teranishi, N. Matsubara, H. Hayashi, and A. Kishimoto

Key Engineering Materials 582 107 - 110 2014年4月

The isothermal conductivity improvement in zirconia-based ceramics under 24 GHz microwave heating 査読

Akira Kishimoto, Keiko Ayano, Takashi Teranishi, Hidetaka Hayashi

MATERIALS CHEMISTRY AND PHYSICS 143 ( 2 ) 486 - 489 2014年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE SA

Under 24-GHz millimetre-wave irradiation heating ionic conductivity of zirconia base ceramics was up to 20 times higher than that of a conventionally-heated sample at the same temperature of 400 degrees C. The degree of enhancement could be altered by changing the stabilising atom from Y to Yb. Enhancement of ionic conduction was prominent in the setup condition of larger self-heating ratio and larger MMW absorbing materials. The isothermal improvement of ionic conductivity under MMW irradiation would be ascribed to the non-thermal effect. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matchemphys.2013.10.002

Relationship Between Phonon Parameters and Oxygen Ion Conductivity for Al-Yb Co-doped Zirconia 査読

Takashi Teranishi, Nami Matsubara, Hidetaka Hayashi, Akira Kishimoto

ELECTROCERAMICS IN JAPAN XVI 582 107 - 110 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：TRANS TECH PUBLICATIONS LTD

The relationship between the optical phonon parameters and the oxygen ion conductivities were investigated for Al-Yb co-doped zirconia ceramics. Intrinsic intragrain ion conductivity, sigma(dc) decreased with increasing Al loading into ytterbia-stabilized zirconia, while the damping parameter of the lattice vibration, gamma(1TO), increased. This phenomenon agreed with findings of our previous study, which revealed a relationship between the sigma(dc), and the gamma(1TO) for zirconia-based ion conductors.

DOI： 10.4028/www.scientific.net/KEM.582.107

Maintaining the mechanical strength of La-, Y-co-substituted zirconia porous ceramics through the superplastically foaming method 査読

Akira Kishimoto, Masanori Okada, Takashi Teranishi, Hidetaka Hayashi

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 581 98 - 103 2013年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE SA

The superplastically foaming method was adopted to make closed-pore inclusive zirconia-based ceramics. Lanthanum oxide was added to monoclinic or tetragonal yttria-stabilised zirconia to reduce the thermal conductivity of the matrix. Sintering and superplastic deformation led to a solid solution and transformation to the cubic phase. The resulting superplastically foamed porous ceramics having a porosity of 45% had only 40% of the thermal conductivity of the fully densified ceramics having the same composition. This value was comparable to that of conventionally fabricated porous ceramics with the same composition and porosity. The superplastically foamed ceramics had 60%, while conventionally fabricated ceramics had only 20%, of the mechanical strength of the fully dense ceramics. (c) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.msea.2013.05.084

Ferroelectric Domain Contribution to the Tunability of Ba08Sr02TiO3 Ceramics 査読

Japanese Journal of Applied Physics 52 09KF06 2013年9月

Ferroelectric Domain Contribution to the Tunability of Ba0.8Sr0.2TiO3Ceramics

Takashi Teranishi, Tsuyoshi Sogabe, Hidetaka Hayashi, Akira Kishimoto, Kazuhiro Fujimori

Japanese Journal of Applied Physics 52 ( 9S1 ) 09KF06 - 09KF06 2013年9月

Thermoelectric efficiency of reduced SrTiO 3 ceramics modified with la and Nb 査読

Takashi Teranishi, Yusuke Ishikawa, Hidetaka Hayashi, Akira Kishimoto, Misaki Katayama, Yasuhiro Inada

Journal of the American Ceramic Society 96 ( 9 ) 2852 - 2856 2013年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ceramics of LaxSr1-xNbyTi 1-yO3 (LSNT) were synthesized under various reducing atmospheres. Covering the specimens with graphite carbon felt under an Ar-gas flow during sintering drastically enhanced the electrical conductivity, σ. Ti K-edge absorption spectra indicated the presence of Ti3+ for heavily reduced specimens. The increase in conductivity was attributed to the 3d band of Ti3+. The maximum value for the figure of merit, ZT, was obtained for strontium titanate ceramics modified with both 5 mol% La and 5 mol% Nb, namely 5/5-LSNT, exhibiting a ZT value of ~0.221 at 473 K. This high ZT value was almost 1.5 × larger than that of the conventional 10 mol% La-doped sample, 10/0-LSNT (ZT~0.144), and was mainly attributed to the larger Seebeck coefficient of the material. © 2013 The American Ceramic Society.

DOI： 10.1111/jace.12379

Lithium ion conductivity of Nd-doped (Li, La)TiO3 ceramics 査読

Takashi Teranishi, Michihiro Yamamoto, Hidetaka Hayashi, Akira Kishimoto

SOLID STATE IONICS 243 18 - 21 2013年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Lithium (Li) ion conductivities of Nd-doped (Li, La)TiO3 (LLNT) ceramics are evaluated as a function of Nd-loading. The bulk ion conductivity, sigma(dc), improves for the specimen with -0.75 mol% Nd. The conductivity of the 0.5 mol% Nd-loaded LLNT is sigma(dc) = 1.26 x 10(-3) S cm(-1) at room temperature. It is the highest conductivity measured, and is 1.33 times higher than that of the non-doped ceramic. The enhancement of the Li ion conductivity with Nd-doping in the LLNTs is attributed to an increase in the volume fraction of the A-site disordered cubic phase. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2013.04.014

Maintaining the mechanical strength of La-, Y- co-substituted zirconia porous ceramics through the superplastically foaming method 査読

Materials Science and Engineering: A 581 98 - 103 2013年6月

Lithium ion conductivity of Nd-doped (Li, La)TiO3 ceramics 査読

Solid State Ionics 243 18 - 21 2013年5月

Effect of millimeter-wave irradiation on cation interdiffusion in the calcium titanate/strontium titanate ceramic couple 査読

Materials Chemistry and Physics 139 825 - 829 2013年5月

Thermoelectric Efficiency of Reduced SrTiO3 Ceramics Modified with La and Nb 査読

Journal of the American Ceramics Society 96 ( 9 ) 2852 - 2856 2013年5月

Effect of millimeter-wave irradiation on cation interdiffusion in the calcium titanate/strontium titanate ceramic couple 査読

Akira Kishimoto, Yukari Kamakura, Takashi Teranishi, Hidetaka Hayashi

MATERIALS CHEMISTRY AND PHYSICS 139 ( 2-3 ) 825 - 829 2013年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE SA

Interdiffusion between the perovskite CaTiO3 and SrTiO3 diffusion couple was investigated in an annealing method using 24-GHz MMW irradiation as the heating source. Interdiffusion was enhanced by MMW irradiation, and the apparent activation energy for interdiffusion decreased 54%, compared with conventional furnace heating. The intrinsic diffusions for both Ca2+ and Sr2+ were also enhanced, although their relative degrees of enhancement differed, partly as a result of differences in MMW absorptivity between the two ceramics. The observed isothermal diffusion enhancement could be ascribed to a nonthermal effect, apart from the differential degree of enhancement between the transport species. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matchemphys.2013.02.038

SUPERPLASTICALLY FOAMING METHOD FOR RELIABLE POROUS CERAMICS 査読

Akira Kishimoto, Takahiro Nakagawa, Takashi Teranishi, Hidetaka Hayashi

SUPERPLASTICITY IN ADVANCED MATERIALS 735 109 - 112 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：TRANS TECH PUBLICATIONS LTD

Porous ceramics incorporate pores to improve several properties including thermal insulation, maintaining inherent ceramic properties such as corrosion resistance and large mechanical strength. Conventional porous ceramics are usually fabricated through an insufficient sintering, leading to degraded strength and durability. Contrary to this, we have innovated superplastically foaming method to make ceramic foam only in the solid state. In this method, the previously inserted foam agent evaporates after the full densification of matrix at around the sintering temperature. Closed pores expand utilizing the superplastic deformation driven by the evolved gas pressure. Based on this concept we fabricated 8mol% yttria stabilized zirconia based porous ceramics and examined the properties concerning the high temperature structural material with thermal insulation.

DOI： 10.4028/www.scientific.net/MSF.735.109

Microscopic Conduction Behavior Analysis on ZrO2-based Ion Conductors by Wideband Conductivity Measurement 査読

Takashi Teranishi, Kosuke Shimizu, Hidetaka Hayashi, Akira Kishimoto

ELECTROCERAMICS IN JAPAN XV 566 141 - 144 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：TRANS TECH PUBLICATIONS LTD

All contributions to the total conductivity, electrolyte electrode interfaces, grain boundaries, ion-hopping, and optical phonons, were determined on the 8 mol% yttria-stabilized zirconia (8YSZ) and 8 mol% ytterbia-stabilized zirconia (8YbSZ) ceramics using the wideband conductivity spectroscopy. Complex conductivity spectra from 10(-1) Hz to 10(14) Hz were successfully obtained. The higher total conductivity of the 8YbSZ ceramics compared to the 8YSZ in wideband frequencies as mainly attributed to difference in the DC conductivity due to universal dielectric response (UDR), sigma(dc); sigma(dc) ((8YbSZ)) > sigma(dc) ((8YSZ)). Other parameters in the UDR and the optical phonon parameters did not greatly influence on the difference in their intrinsic conductivities.

DOI： 10.4028/www.scientific.net/KEM.566.141

Superplastically Foaming Method for Reliable Porous Ceramics 査読

Materials Science Forum 735 109 - 112 2012年12月

塑性発泡法によるセラミックスへの螺旋状連通閉気孔の導入査読

粉体および粉末冶金 2012年2月

Thermoelectric Property of Polycrystalline Aluminum-Doped Zinc Oxide Enhanced by Micropore Foaming 査読

Journal of the American Ceramic Society 95 ( 2 ) 690 - 695 2012年2月

Thermoelectric Property of Polycrystalline Aluminum-Doped Zinc Oxide Enhanced by Micropore Foaming 査読

Takashi Teranishi, Yosuke Mori, Hidetaka Hayashi, Akira Kishimoto

JOURNAL OF THE AMERICAN CERAMIC SOCIETY 95 ( 2 ) 690 - 695 2012年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

A unique micropore foaming technique was used to enhance the thermoelectric properties of polycrystalline aluminum-doped zinc oxide (AZO). Silicon carbide (alpha-SiC) and aluminum nitride (AlN) were used as foaming precursors. Thermoelectric conductivity, kappa, decreased on addition of both precursors, increasing the porosity. Electric conductivity, sigma, decreased upon addition of alpha-SiC, and subsequent addition of AlN reversed the effect. This phenomenon is due to the chemical reactions that occur upon addition of each precursor: the active oxidation of alpha-SiC and the decomposition reaction of AlN. The Seebeck coefficient, S, for 0.5 mol% AlN-doped AZO (Al0.005Zn0.995O, AZO-0.005) was more than twice that of conventional non-doped AZO. Accordingly, the power factor and the figure of merit, ZT, for the porous AlN-doped AZO-0.005 were 4.9 and 5.8 times those of the conventional polycrystalline AZO, respectively, demonstrating that the compositionally optimized porous AZO exhibited excellent thermoelectric properties at high temperatures.

DOI： 10.1111/j.1551-2916.2011.04837.x

ミリ波-HIP複合焼結法で焼成したAINセラミックスに及ぼす還元雰囲気の影響査読

粉体および粉末冶金 2012年1月

Quasi-millimeter-wave absorption behavior in Y/Yb-stabilized zirconia ceramics 査読

Applied Physics Letters 100 242903 2012年1月

超塑性発泡法における窒化物系新規発泡剤の探索と特性評価査読

耐火物 2012年1月

Complex Conductivity Using Wideband Spectroscopy for Yttria/Ytterbia-Stabilized Zirconia Ceramics 査読

Takashi Teranishi, Kosuke Shimizu, Naoki Akiyama, Hidetaka Hayashi, Akira Kishimoto, Kazuhiro Fujimori

JAPANESE JOURNAL OF APPLIED PHYSICS 51 ( 1 ) 2012年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPAN SOC APPLIED PHYSICS

Complex conductivity wideband spectra from 10(-1) to 10(14) Hz (100 THz) were determined for 8 mol% yttria-stabilized zirconia (8YSZ) and 8 mol% ytterbia-stabilized zirconia (8YbSZ) ceramics. The contributions of electrolyte-electrode interfaces, grain boundaries, intragrain ion-hopping, and optical phonons were quantified to relate the microscopic conduction behavior to the overall conductivity. Intrinsic conductivity was mostly governed by ion-hopping. For both 8YSZ and 8YbSZ, ion-hopping followed the universal dielectric response (UDR) for broadband frequencies except for the phonon dispersion frequencies. The higher overall conductivities of the 8YbSZ ceramics compared to the 8YSZ ones were attributed to differences in the UDR contributions. The dominant factor determining the difference in the intrinsic conductivity in broadband frequencies from direct current (DC) to microwave between the 8YSZ and 8YbSZ ceramics was the DC conductivity due to UDR, sigma(dc), where sigma(dc(8YbSZ)) > sigma(dc(8YSZ)). Other parameters in the UDR and the optical parameters did not greatly influence the intrinsic conductivities. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.011102

Broadband spectroscopy of the complex conductivity of polycrystalline yttria-stabilized zirconia 査読

Takashi Teranishi, Hidetaka Hayashi, Akira Kishimoto, Takaaki Tsurumi

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS 177 ( 1 ) 69 - 73 2012年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Broadband conductivity spectra from 100 to 10(14) Hz (100 THz) were acquired for yttria-stabilized zirconia (10 mol% Y(2)O(3)-doped ZrO(2), 10YSZ) to quantify contributions from conduction due to the electrolyte electrode interface, grain boundaries, universal dielectric response (UDR), and optical phonons. The UDR contribution governed the intrinsic conductivity at all frequencies except specific frequencies in the terahertz range, where phonon contributions governed conductivity for both ceramics and single crystals. UDR parameters sigma(0) and sigma(dc), increased with increasing temperature, resulting in increased microwave conductivity. The complex conductivity converged at frequencies of hundreds of gigahertz due to a decrease in the power-law constants, with increasing temperature. The optical phonon contribution to the total conductivity, due to an increase in the damping factor gamma(1TO) with increasing temperature, was small, while the phonon-mode frequency omega(1TO) affected the microwave conductivity of 10YSZ. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.mseb.2011.09.039

Complex Conductivity Using Wideband Spectroscopy for Yttria/Ytterbia-Stabilized Zirconia Ceramics 査読

Japanese Journal of Applied Physics 51 011102 2011年12月

Broadband spectroscopy of the complex conductivity of polycrystalline yttria-stabilized zirconia 査読

Materials Science and Engineering B 177 69 - 73 2011年10月

Effect of varying the ratio of matrix/dispersoid particle size on the piezoresistivity of alumina/carbon-black composite ceramics 査読

Akira Kishimoto, Yuto Takagawa, Takashi Teranishi, Hidetaka Hayashi

MATERIALS LETTERS 65 ( 14 ) 2197 - 2200 2011年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Alumina/carbon-black composite ceramics with different percolation thresholds were fabricated by changing the size ratio of constituent particles. The dependence of resistivity on pressure was established for each sample. The compositional dependence of resistivity can be explained by percolation theory. The percolation threshold decreases with increasing alumina/carbon-black particle size ratio. The pressure dependence of the resistivity increases as the composition approaches the percolation threshold. When the relative composition at the percolation threshold is fixed, the sensitivity increases with increasing matrix/dispersoid initial particle size ratio. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matlet.2011.04.042

Effect of varying the ratio of matrix/dispersoid particle size on the piezoresistivity of alumina/carbon-black composite ceramics 査読

Materials Letters 65 2197 - 2200 2011年4月

Size effect and domain-wall contribution of barium titanate ceramics 査読

Takuya Hoshina, Yoichi Kigoshi, Saki Hatta, Takashi Teranishi, Hiroaki Takeda, Takaaki Tsurumi

Ferroelectrics 402 ( 1 ) 29 - 36 2010年11月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Barium titanate (BaTiO3) ceramics with various grain sizes from 0.7 to 13 μm were prepared by a conventional sintering method and a two-step sintering method. The permittivity of the BaTiO3 ceramics with an average grain size of 1.1 μm exhibited a maximum around 8,000. By ultrawide range dielectric spectroscopy, the domain-wall contribution to the permittivity was investigated. For the BaTiO3 ceramics with grain sizes over 1 μm, the dipole and ionic polarizabilities were enhanced by the high domain density. In contrast, for the BaTiO3 ceramics with grain sizes below 1 μm, these polarizabilities were weakened. Copyright © 2010 Taylor & Francis Group, LLC.

DOI： 10.1080/00150191003697179

Effects of oxygen vacancies and grain sizes on the dielectric response of BaTiO3 査読

Applied Physics Letters 97 212907-1 - 212907-3 2010年11月

Analysis of polarization behavior in relaxation of BaTiO<inf>3</inf>-based ferroelectrics using wideband dielectric spectroscopy 査読

Takashi Teranishi, Takuya Hoshina, Hiroaki Takeda, Takaaki Tsurumi

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 57 ( 10 ) 2118 - 2126 2010年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Wideband dielectric spectra from the kilohertz to terahertz range are discussed for BaTiO3-based ferroelectrics. Ceramics of BaTiO3 (BT), Ba0.6Sr0.4TiO3 (BST-0.6), and BaZr0.25Ti0.75O3 (BZT-0.25) were selected as normal ferroelectrics, ferroelectrics with diffuse phase transition (DPT ferroelectrics), and relaxor ferroelectrics, respectively. The variation of ionic polarization in both BT and BST-0.6 ceramics with temperature could be explained by the softening of the soft phonon mode. In BZT-0.25, a permittivity anomaly at the dielectric maximum temperature (Tm) at low frequencies is not attributed to the softening of the soft phonon mode, but originates from the permittivity derived from the εdipole polarization (dipole). Relaxor behavior in BZT-0.25 is derived from the increase in the depression of εdipole on cooling across the Tm with increasing frequency. In εdipole polarization, BT, BST- 0.6, and BZT-0.25 all exhibited a similar tendency of εdipole above the Curie temperature (Tc) and Tm. However, behavior of εdipole below the Tc can be explained by the ferroelectric domains in BT, whereas the variation of εdipole below the Tm could be explained by growth process of polar nanoregions (PNRs) in BST-0.6 and BZT-0.25. Regarding this, BT can be distinguished from BST-0.6 and BZT-0.25. Relaxation in BT could be interpreted as successive change in polarization mechanism from normal ferroelectrics to relaxor ferroelectrics via DPT ferroelectrics. © 2010 IEEE.

DOI： 10.1109/TUFFC.2010.1667

Analysis on Dipole Polarization of BaTiO3-based Ferroelectric Ceramics by Raman Spectroscopy 査読

Journal of the Ceramic Society of Japan 118 679 - 682 2010年8月

Analysis on dipole polarization of BaTiO3-based ferroelectric ceramics by Raman spectroscopy 査読

Takashi Teranishi, Naohiro Horiuchi, Takuya Hoshina, Hiroaki Takeda, Takaaki Tsurumi

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 118 ( 1380 ) 679 - 682 2010年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Analysis of asymmetric Raman line shape disclosed the variation of phonon correlation length in A(1)(3TO) mode, L-A1(3TO), with temperature in the ceramics of BaTiO3 (BT), Ba0.6Sr0.4TiO3 (BST-0.6) and BaZr0.25Ti0.75O3 (BZT-0.25), namely normal ferroelectrics, ferroelectrics with diffuse phase transition (DPT ferroelectrics) and relaxor ferroelectrics, respectively. In BT, L-A1(3TO) exhibited steep increase at the Curie temperature (T-c) on cooling. This is attributed to the formation of the ferroelectric domains at the T-c. Both BST-0.6 and BZT-0.25 showed gradual increase in L-A1(3TO) on cooling across the dielectric maximum temperature (T-m), indicating the continuous increase in the average size of the polar nanoregions (PNRs). Normal ferroelectrics can be distinguished from DPT and relaxor ferroelectrics in this point. L-A1(3TO) of BZT-0.25 was longer than that of BST-0.6 near the T-m. This suggests the size of PNRs in BZT-0.25 is larger than that in BST-0.6. Huge dipole polarization of BZT-0.25, giving rise to the strong relaxor behavior, could be originated from the contribution of the large PNRs near the T-m. DPT ferroelectrics can be also differentiated from relaxor ferroelectrics in terms of the average size of PNRs. (C) 2010 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.118.679

Wide Band Dielectric Spectroscopy at Ferroelectric Phase Transition of BaTiO3 Ceramics 査読

Japanese Journal of Applied Physics 49 041506-1 - 041506-4 2010年4月

Dielectric Properties of Barium Titanate Ceramics with Nano-Sized Domain 査読

Yoichi Kigoshi, Saki Hatta, Takashi Teranishi, Takuya Hoshina, Hiroaki Takeda, Osamu Sakurai, Takaaki Tsururni

Key Engineering Materials (ELECTROCERAMICS IN JAPAN XIII) 445 27 - 30 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：TRANS TECH PUBLICATIONS LTD

Barium titanate (BaTiO3) ceramics with various grain sizes from 0.7 to 13 mu m on average were prepared by a conventional sintering method, a two-step sintering method and a rate controlled two-step sintering method. The permittivity of the ceramics was increased with decreasing grain size to 1.1 mu m on average. However, the permittivity of the ceramics was decreased when the grain size was below 1 mu m. The field emission scanning electron microscope (FE-SEM) observations revealed that the 900 domain width decreased with decreasing the grain size. By ultrawide range dielectric spectra from kHz to THz range of the BaTiO3 ceramics, the domain contribution to the permittivity was investigated. For the BaTiO3 ceramics with grain sizes over 1 mu m, the dipole polarizability and the ionic polarizability were enhanced by high domain-wall density. In contrast, for the BaTiO3 ceramics with grain sizes below 1 mu m, these polarizabilities were weakened.

DOI： 10.4028/www.scientific.net/KEM.445.27

Wide Range Dielectric Spectroscopy of Barium Strontium Titanate Ceramics 査読

Takashi Teranishi, Takuya Hoshina, Hiroaki Takeda, Takaaki Tsurumi

Key Engineering Materials (ASIAN CERAMIC SCIENCE FOR ELECTRONICS III AND ELECTROCERAMICS IN JAPAN XII) 421-422 273 - 276 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：TRANS TECH PUBLICATIONS LTD

Wide band dielectric spectroscopy was applied from kHz to THz region for the analysis of both the ionic and the dipole polarization in Ba(0.6)Sr(0.4)TiO(3) ceramics. The dielectric permittivity above the dielectric maximum temperature (T(m)) is mostly dominated by the ionic polarization, while that below T(m) is governed by the dipole polarization. Dielectric permittivity given by the dipole polarization increased and the relaxation frequency decreased with decreasing temperature. These phenomena are related to a increase of the size of polar nanoregions (PNRs).

DOI： 10.4028/www.scientific.net/KEM.421-422.273

Wide Range Dielectric Spectroscopy on Perovskite Dielectrics 査読

Materials Science and Engineering: B 161 55 - 60 2009年4月

Polarization Behavior in Diffuse Phase Transition of BaxSr1−xTiO3 Ceramics 査読

Journal of Applied Phyics 105 054111-1 - 054111-5 2009年3月

Ultrawideband Dielectric Spectroscopy of BaZrxTi1−xO3 Ceramics and Its Microscopic Mechanism of Polarization 査読

Journal of Applied Phyics 105 114102-1 - 14102-4 2009年1月

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