Faculty Profiles - KIWA Toshihiko

MISC - KIWA Toshihiko

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THz波ケミカル顕微鏡による発電中の燃料電池触媒反応解析

日下鉄也, 萩原隆文, 堺健司, 紀和利彦, 塚田啓二

応用物理・物理系学会中国四国支部合同学術講演会講演予稿集 2013 2013

テラヘルツ波バイオ検査装置の開発と現状

紀和利彦

日本分光学会テラヘルツ分光部会シンポジウム講演要旨集 2013 2013

白金ナノ薄膜の水素応答評価

武市修蔵, 奥井貴博, 牛田祐貴, 堺健司, 紀和利彦, 塚田啓二

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 64th 2013

Compact Vibrating-Sample Magnetometer using High-T_c SQUID and Sample Shape Dependency

SAARI Mohd Mawardi, TAKAGI Ryuuki, SAKAI Kenji, KIWA Toshihiko, TSUKAMOTO Akira, ADACHI Seiji, TANABE Keiichi, KANDORI Akihiko, TSUKADA Keiji

Technical report of IEICE. SCE 112 ( 138 ) 31 - 36 2012.7

Language：English Publisher：The Institute of Electronics, Information and Communication Engineers

In this study, we have developed a compact vibrating-sample magnetometer that utilizing a normal pickup coil and an SQUID. Optimizations on dependency of sample shape, sample position relative to pickup coil etc. were performed by experiment and simulation results. The present measurement system successfully measured the weak diamagnetism of water and exhibited the sensitivity of 1×10^<-7> emu.

CiNii Article

CiNii Books

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Work function shifts of catalytic metals under hydrogen gas visualized by terahertz chemical microscopy. International journal

Toshihiko Kiwa, Takafumi Hagiwara, Mitsuhiro Shinomiya, Kenji Sakai, Keiji Tsukada

Optics express 20 ( 11 ) 11637 - 42 2012.5

Language：English Publisher：OPTICAL SOC AMER

Terahertz chemical microscopy (TCM) was applied to visualize the distribution of the work function shift of catalytic metals under hydrogen gas. TCM measures the chemical potential on the surface of a SiO(2)/Si/sapphire sensing plate without any contact with the plate. By controlling the bias voltage between an electrode on the SiO(2)/ surface and the Si layer, the relationship between the voltage and the THz amplitude from the sensing plate can be obtained. As a demonstration, two types of structures were fabricated on the sensing plate, and the work function shifts due to catalytic reactions were visualized.

DOI： 10.1364/OE.20.011637

Development of a compact moving-sample magnetometer using high-Tc superconducting quantum interference device

Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Akira Tsukamoto, Seiji Adachi, Keiichi Tanabe, Akihiko Kandori, Keiji Tsukada

Japanese Journal of Applied Physics 51 ( 4 PART 1 ) 046601 2012.4

Language：English Publisher：IOP PUBLISHING LTD

We developed a compact moving-sample magnetometer that uses a high-temperature superconductor-superconducting quantum interference device (high-T c SQUID) to directly measure the flux coupled to a normal detection coil from a sample's magnetic moment in the presence of an external DC magnetic field. The moving-sample method is employed by inserting the sample between the poles of a DC electromagnet and vibrating the sample along the axis perpendicular to the external field axis using an actuator at a frequency of 2.693 Hz. First, the magnetic field of the sample is transferred by a first-order differential normal Cu coil to a SQUID for detection. Then, the SQUID output is fed to a lock-in amplifier for detection. The critical feature of the system design is the use of high-T c SQUID, which enables the realization of a compact system. The basic characteristics of the developed system are presented, and the current system exhibited a detection limit of 1 x 10 -7 emu. © 2012 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.51.046601

Web of Science

Scopus

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Electric Characteristics of a Loop in Which Two Junctions between a Catalytic Metal and a Noncatalytic Metal Are under Different Hydrogen Gas Concentrations

Keiji Tsukada, Kenji Sakai, Toshihiko Kiwa

APPLIED PHYSICS EXPRESS 5 ( 3 ) 034102 2012.3

Language：English Publisher：JAPAN SOC APPLIED PHYSICS

To investigate the localized electrochemical properties of an electrode composed of platinum (Pt), a thin-film loop containing two junctions between the catalytic metal Pt and the noncatalytic metal titanium was fabricated. When the loop was open and only one junction was exposed to 10% hydrogen in nitrogen gas, an output voltage change of about 30 nV was generated between these two junctions. The electron density change due to the equilibrium reaction of hydrogen dissociation along the part exposed to hydrogen induced a balance between the diffusion and drift caused by the electric field at both ends of the Pt film. (c) 2012 The Japan Society of Applied Physics

DOI： 10.1143/APEX.5.034102

Web of Science

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Changes in work function and electrical resistance of Pt thin films in the presence of hydrogen gas

Keiji Tsukada, Hirotsugu Inoue, Fumiya Katayama, Kenji Sakai, Toshihiko Kiwa

Japanese Journal of Applied Physics 51 ( 1 ) 015701 2012.1

Language：English Publisher：JAPAN SOC APPLIED PHYSICS

The changes in the electrical properties, such as work function and resistance, of Pt thin films in the presence of hydrogen gas were studied. They were simultaneously measured with a flow-through cell at different concentrations of hydrogen gas in atmosphere containing gaseous nitrogen and that containing air. The resistance was measured by a four-terminal sensing method and the relative work function changes were measured using a field effect transistor. In both atmospheres, the resistance decreased as the concentration of hydrogen gas increased. This result was repeatable only in air because of the differences in the dynamic mechanism of increased density of electrical carriers inside the Pt film as a result of diffused H atoms. In the nitrogen atmosphere, the diffused H atoms were not easily released because of the surface barrier. On the other hand, oxygen gas reacted with H atoms at the surface and this reaction accelerated atom release into air. The work function showed repeatable responses in both atmospheres, but the response characteristics were different. The equilibrium reaction between the adsorption and desorption of hydrogen occurred at the surface in the nitrogen atmosphere, whereas the equilibrium reaction of hydrogen and oxygen to form water molecules occurred in air. The changes in work function and resistance in the presence of hydrogen were due to changes in dissociated hydrogen intensity in the bulk, as well as to the surface reactions. © 2012 The Japan Society of Applied Physics.

DOI： 10.1143/JJAP.51.015701

Web of Science

Scopus

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Non-destructive evaluation system using high-Tc SQUID

紀和利彦, 福留陽平, 堺健司, 塚本晃, 安達成司, 田辺圭一, 神鳥昭彦, 塚田啓二

電子情報通信学会技術研究報告 111 ( 418(SCE2011 19-26) ) 11 - 16 2012

Biosensing by a terahertz chemical microscope.

紀和利彦

応用物理 81 ( 4 ) 298 - 303 2012

テラヘルツ波ケミカル顕微鏡による抗原非標識定量計測

高橋慎治, 天満陽, 紀和利彦, 堺健司, 塚田啓二

応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集 2012 2012

高温超伝導SQUIDを用いた交流磁気特性計測システムの開発

山口嘉竜, 前田敏志, 浜崎大地, 堺健司, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

応用物理学関係連合講演会講演予稿集(CD-ROM) 59th 2012

薄膜抵抗型水素センサの開発

奥井貴博, 片山文哉, 堺健司, 紀和利彦, 塚田啓二

電気学会全国大会講演論文集 2012 ( 3 ) 2012

参照電極が不要なイオンセンサの応答機構解析

山本貴文, 小森達也, 小田和代, 堺健司, 紀和利彦, 塚田啓二

電気学会全国大会講演論文集 2012 ( 3 ) 2012

Characterization of New Structural Sodium Ion Sensor using Electrochemical Impedance Method

小森達也, 山本貴文, 堺健司, 紀和利彦, 塚田啓二

電気学会ケミカルセンサ研究会資料 CHS-12 ( 1-16 ) 2012

異なる白金薄膜構造をもつ抵抗変化式水素センサの応答解析

奥井貴博, 堺健司, 紀和利彦, 塚田啓二

センサ・マイクロマシンと応用システムシンポジウム(CD-ROM) 29th 2012

保温材下配管外面欠陥の磁気的検査装置の開発-その2

橋本源基, 堺健司, 紀和利彦, 塚田啓二

日本非破壊検査協会講演大会講演概要集 2012 2012

HTS-SQUIDを用いた磁気緩和測定用小型磁化率計の開発

堺健司, SAARI Mohd Mawardi, 浜崎大地, 紀和利彦, 円福敬二, 塚田啓二

応用物理学会学術講演会講演予稿集(CD-ROM) 73rd 2012

高温超伝導SQUIDを用いた直流磁化率計の高感度計測法

SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

応用物理学会学術講演会講演予稿集(CD-ROM) 73rd 2012

HTS-SQUIDを用いた電気磁気化学計測システムの開発

紀和利彦, 宮崎真伍, 高木竜輝, 堺健司, 塚田啓二

応用物理学会学術講演会講演予稿集(CD-ROM) 73rd 2012

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