研究者詳細 - 藤井　達生

論文 - 藤井　達生

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青色無機顔料コバルトブルーの色調におよぼすコバルト原料化合物の影響査読

米田美佳, 辰己祐哉, 三野泰志, 中曽浩一, 後藤邦彰, 中西真, 藤井達生, 小西康裕, 野村俊之

粉体工学会誌 56 ( 8 ) 446 - 451 2019年8月

In situ Mossbauer analysis of bacterial iron-oxide nano-particles for lithium-ion battery

Ryo Sakuma, Hideki Hashimoto, Tatsuo Fujii, Jun Takada, Naoaki Hayashi, Mikio Takano

HYPERFINE INTERACTIONS 240 ( 1 ) 2019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：SPRINGER INTERNATIONAL PUBLISHING AG

Nanometric amorphous iron-based oxides of bacterial origin show a great potential as an Fe3+/Fe-0 conversion anode material for lithium-ion batteries. By means of in situ Mossbauer spectroscopy, chemical states of Fe ions were examined under the discharge-charge process of the bacterial iron-oxide electrode in a lithium-ion half-cell. As for the first discharge process, the successive reduction of Fe3+-> Fe2+-> Fe-0 occurred in the electrode as a function of the cell voltage. While on the charge process, Fe-0 in the electrode was oxidized directly to Fe3+ without going through Fe2+.

DOI： 10.1007/s10751-019-1639-y

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Solid-state synthesis and characterization of cobalt blue core-shell pigment particles

Mika Yoneda, Kuniaki Gotoh, Makoto Nakanishi, Tatsuo Fujii, Yasuhiro Konishi, Toshiyuki Nomura

JOURNAL OF THE AMERICAN CERAMIC SOCIETY 102 ( 6 ) 3468 - 3476 2019年6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

Cobalt blue is one of the most chemically and thermally stable blue pigments. However, cobalt is scarce and expensive. To minimize the use of cobalt and reduce production costs and toxicity, cobalt blue core-shell pigments were synthesized by a solid-state method, which is cheaper than a liquid-phase reaction. Small cobalt hydroxide particles and large -alumina particles, in various ratios, were used as the starting materials. The dry mixed powders were calcined at 1200 degrees C for 2hours. Elemental mappings of the surfaces and cross sections of the synthesized particles showed that the cobalt blue had a core-shell structure. X-ray diffraction patterns showed that the synthesized cobalt blue consisted of an -alumina core and a cobalt aluminate shell. The color tone of the synthesized cobalt blue was evaluated from the lightness (L*) and chroma (C*) values. The color tone of the cobalt blue synthesized in this study was almost same as those of commercially available samples although the cobalt molar fraction was lower than the stoichiometric ratio (Co/(Co+Al)=0.33, Co/Al=0.5) which was calculated from the chemical reaction formula.

DOI： 10.1111/jace.16191

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Bright greenish-yellow pigments based on Sc<inf>2−</inf><inf>x</inf>Fe<inf>x</inf>O<inf>3</inf> solid solutions with bixbyite structure

Hideki Hashimoto, Kotaro Sayo, Hidetaka Asoh, Tatsuo Fujii, Mikio Takano, Atsunobu Masuno, Atsunobu Masuno, Atsunobu Masuno

Materials Research Bulletin 109 190 - 194 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Elsevier Ltd An oxide system Sc2−xFexO3 prepared by a conventional solid-state reaction method was found to change its color from the well-known reddish color at x = 2.0 to a yellowish color at x ≈ 0.6 and to a greenish-yellow color at 0.2 ≤ x ≤ 0.4. According to the structural characterization results for this system, the monophasic corundum phase region persists for 1.6 ≤ x ≤ 2.0, whereas the bixbyite-type phase is monophasic for 0 ≤ x ≤ 1.0. The intermediate region of 1.2 ≤ x ≤ 1.4 is a mixed region. Because green is a rare color for iron oxides, powder of the most typical composition, x = 0.4, with (L*, a*, b*) coordinates of (77.3, −0.5, 51.0) was tested as a pigment for a Japanese-style painting and also as an overglaze enamel on porcelain; reasonably good results were obtained.

DOI： 10.1016/j.materresbull.2018.09.035

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Influence of cobalt source compounds on the color tone of cobalt blue inorganic pigment

Mika Yoneda, Yuya Tatsumi, Yasushi Mino, Koichi Nakaso, Kuniaki Gotoh, Makoto Nakanishi, Tatsuo Fujii, Yasuhiro Konishi, Toshiyuki Nomura

Journal of the Society of Powder Technology, Japan 56 ( 8 ) 446 - 451 2019年

掲載種別：研究論文（学術雑誌）

The color tone of pigments is affected by various factors such as crystal structure and particle size. These characteristics should be determined by synthesis condition. In this study, the influence of cobalt source on the color tone of cobalt blue pigment was investigated. Cobalt blue (CoAl2O4) was synthesized by solid-state reaction method. Co3O4 and Co(OH)2 with two different particle sizes were used as the cobalt source, and γ-Al2O3 was used as the aluminum source. The products were characterized by spectrophotometry, XRD, SEM, and TG/DTA. It was revealed that the chroma of the synthesized cobalt blue depends on the cobalt source. The cobalt blue synthesized using smaller size Co(OH)2 showed most vivid color. It was suggested that the number of the contact points between the starting materials increased with decreasing the particle size, leading to the progress of the reaction.

DOI： 10.4164/sptj.56.446

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Cathepsin K inhibitor causes changes in crystallinity and crystal structure of newly-formed mandibular bone in rats 査読国際誌

Y. Yoshioka, E. Yamachika, M. Nakanishi, T. Ninomiya, K. Nakatsuji, Y. Kobayashi, T. Fujii, S. Iida

British Journal of Oral and Maxillofacial Surgery 56 ( 8 ) 732 - 738 2018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 BV

Cathepsin K inhibitors are new drugs with the potential for the treatment of osteoporosis because they sustain bony remodelling better than bone resorption inhibitors such as bisphosphonates. The treatment of osteoporosis with inhibitors of bony resorption is associated with osteonecrosis of the jaw, as the deterioration in bony quality that they induce is thought to be one of its causes. The quality of bone is delineated by structural and material characteristics (which include the degree and quality of mineralisation, and depends on the content of proteoglycan and the structural integrity of the bony collagen).1,2 Animal and clinical studies have shown that cathepsin K inhibitors improve the mineral density and structural characteristics of bone, but their effect on the rest remains unknown. We therefore hypothesised that these inhibitors will affect the material characteristics of newly-formed mandibular bone. To verify our hypothesis, we used Raman microspectroscopy to examine such bone in rats that were given a cathepsin K inhibitor, and found unusual crystallinity and an increased substitution of carbonate (CO32-) in its crystal structure.

DOI： 10.1016/j.bjoms.2018.08.003

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スパッタ法によるエピタキシャルFe_3-xTi_xO₄固溶体薄膜の作製査読

西村和泰, 北園昌弘, 中西真, 藤井達生

粉体および粉末冶金 65 ( 9 ) 585 - 588 2018年9月

Molecular alterations of newly formed mandibular bone caused by zoledronate 国際誌

Y. Yoshioka, E. Yamachika, M. Nakanishi, T. Ninomiya, K. Nakatsuji, M. Matsubara, N. Moritani, Y. Kobayashi, T. Fujii, S. Iida

International Journal of Oral and Maxillofacial Surgery 47 ( 9 ) 1206 - 1213 2018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：Elsevier BV

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.

DOI： 10.1016/j.ijom.2018.02.002

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Cuticle network and orientation preference of photonic crystals in the scales of the weevil Lamprocyphus augustus

R. Ebihara, H. Hashimoto, J. Kano, T. Fujii, S. Yoshioka

Journal of The Royal Society Interface 15 ( 145 ) 20180360 - 20180360 2018年8月

掲載種別：研究論文（学術雑誌）出版者・発行元：The Royal Society

This paper reports the structural and optical investigations of the structural colour of the weevil
<italic>Lamprocyphus</italic>
<italic>augustus</italic>
. The photonic crystal structure within the weevil's scales was investigated using sequential focused ion-beam milling and scanning electron microscopy imaging. We carefully analysed the reconstructed three-dimensional structure to determine the unit cell of the photonic crystal. It was found that the cuticle network of the cubic unit cell perfectly matches the previously reported diamond-based network. However, different results were obtained for the crystal orientations of the small crystal domains that comprise the entire photonic crystal structure in the scales:
<monospace><111></monospace>
directions are highly preferred along the surface normal of the scale. This finding explains the fact that the scale is almost uniformly coloured despite the multi-domain structure. It is confirmed experimentally and theoretically that the wavelength range of the reflection band corresponds to the gap of the photonic band.

DOI： 10.1098/rsif.2018.0360

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その他リンク： https://royalsocietypublishing.org/doi/full-xml/10.1098/rsif.2018.0360

電場印加前後でのBaTiO₃内殻原子軌道のエネルギー準位計測

押目典宏, 伊藤満, 藤井達生, 保井晃, 狩野旬, 池永英司, 安井伸太郎, 日隈聡士, 池田直, 濱嵜容丞, 安原颯, 横谷尚睦

日本物理学会講演概要集 73 2571 - 2571 2018年

分極効果で変調される強誘電体BaTiO₃の電子構造

押目典宏, 伊藤満, 藤井達生, 保井晃, 狩野旬, 池永英司, 安井伸太郎, 日隈聡士, 池田直, 濱嵜容丞, 安原颯, 横谷尚睦

日本物理学会講演概要集 72 2307 - 2307 2017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

21aPS-115 金属-強誘電体接合系における触媒作用

重名智博, 狩野旬, 池田直, 藤井達生, 大久保智子

日本物理学会講演概要集 71 2708 - 2708 2016年

α-Fe₂O₃, Fe₃O₄, FeO粉末のバンド構造

押目典宏, 狩野旬, 岡本拓巳, 池田直, 藤井達生

日本物理学会講演概要集 71 2545 - 2545 2016年

記述言語：日本語出版者・発行元：一般社団法人日本物理学会

<p>前回の日本物理学会2016年次大会では，強誘電体バンド構造のイオン欠損効果を光反射率スペクトルと光電子収量分光スペクトルから議論した。今回はFeイオン価数の異なるFe酸化物を3種類用意し，前回と同様の測定を行ったところ，FeとOの比率に対しバンド構造のエネルギー深さが系統的に変化することがわかったので，今回報告する。</p>

DOI： 10.11316/jpsgaiyo.71.2.0_2545

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Mnをドープした単結晶Yb₂Fe₃O₇の誘電特性

烏谷友之, 藤原孝将, 藤井達生, 戸取和大, 福永守, 堀部陽一, 狩野旬, 池田直

日本物理学会講演概要集 71 2543 - 2543 2016年

記述言語：日本語出版者・発行元：一般社団法人日本物理学会

<p>Yb_2_Fe_3_O_7_は層状希土類複電荷酸化鉄YbFe_2_O_4_の同族物質であり,どちらもWレイヤーと呼ばれるFe-Oの二重層を持つ。Wレイヤー内では電子が規則配列をし,電子の偏りが起こり,電子の濃淡による新しい機構の強誘電性が発現すると期待されている。最近MnをドープしたYb_2_Fe_3_O_7_のセラミックのP-Eヒステリシスループが報告された。だがセラミック試料では粒界にトラップされた電荷の効果も起こり得る。今回我々は単結晶を作成し、誘電性の異方性を調べ報告する。</p>

DOI： 10.11316/jpsgaiyo.71.2.0_2543

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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

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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

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

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

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Mössbauer spectrum of high-pressure synthesized ilmenite-type FeGeO<inf>3</inf> 査読

T. Fujii, D. Nakatsuka, M. Nakanishi, J. Takada, T. Yoshino

Hyperfine Interactions 226 ( 1-3 ) 275 - 280 2014年4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）

Ilmenite-type FeGeO3was prepared by high-pressure synthesis technique using a Kawai-type multi-anvil apparatus at 23.5 GPa and 500 °C. The effects of post annealing on the high-pressure synthesized samples were investigated by XRD analysis, Mössbauer spectroscopy and SQUID-magnetization measurements. The subsequent annealing after the high-pressure synthesis was effective to improve the crystallinity and increased the crystallite size of the ilmenite-type FeGeO3. The room temperature Mössbauer spectrum was composed of sharp paramagnetic doublets assigned to Fe2+. The well-crystallized ilmenite-type FeGeO3showed typical antiferromagnetic behavior with the Néel temperature of 79 K, while the as-prepared sample without annealing demonstrated the superparamagnetic characteristics with larger magnetization. © 2014 Springer International Publishing Switzerland.

DOI： 10.1007/s10751-014-1014-y

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その他リンク： http://orcid.org/0000-0002-5422-7396

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