研究者詳細 - 野上　由夫

論文 - 野上　由夫

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低次元有機錯体の低温・高圧下構造測定

野上由夫, 大嶋孝吉

日本結晶学会誌 41 ( 1 ) 48 - 56 1999年2月

記述言語：日本語出版者・発行元：The Crystallographic Society of Japan

Various ground states such as superconductivity, Mott insulator, CDW and charge ordering for low-dimensional organic complexes, are studied using X-ray. Techniques including homemade cameras and know-hows for low temperature and high pressure X-ray measurements are presented.

DOI： 10.5940/jcrsj.41.48

その他リンク： https://jlc.jst.go.jp/DN/JALC/00059771517?from=CiNii

High Pressure Structures of Organic Low Dimensional Conductor DCNQI Compounds 査読

Y. Nogami, S. Hayashi, T. Date, K. Oshima, K. Hiraki, K. Kanoda, K. Hiraki, K. Kanoda

Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu 7 404 - 406 1998年

記述言語：英語掲載種別：研究論文（学術雑誌）

Using X-ray and DAC, room-temperature crystal structures under physical pressure(PP) were solved for DCNQI-Cu compounds which exhibit particular metal-insulator(M-I) transition owing to their electronic low dimensionality(CDW) and strong correlation(Mott). This M-I transition is known to be triggered with moderate(=small) PP or chemical substitution(chemical pressure:CP). Observed high pressure structures were compared with theoretical structure determinations. From the structural viewpoint, relation between PP and CP effects on the M-I transition was discussed, [organic conductor, metal-insulator transition, charge density wave, Mott transition, X-ray diffraction]. © 1998, The Japan Society of High Pressure Science and Technology. All rights reserved.

DOI： 10.4131/jshpreview.7.404

Low temperature structure of the alpha PRIME;-(BEDT-TTF)(2)IBr2 organic magnetic semiconductor 査読

M Watanabe, M Nishikawa, Y Nogami, K Oshima, G Saito

JOURNAL OF THE KOREAN PHYSICAL SOCIETY 31 ( 1 ) 95 - 98 1997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：KOREAN PHYSICAL SOC

A low temperature structure analysis for the alpha'-(BEDT-TTF)(2)IBr2 compound has been carried out. The temperatures studied include the regions where anomalous behavior of the conductivity and the susceptibility exist. It has been found that particular terminal ethylene groups of the BEDT-TTF molecules in the unit cell show anomalous temperature-dependent behavior. An anomalous behavior of the unit-cell parameter gamma has been also observed. These are considered to be related with the anomaly of the conductivity around 200 K. No remarkable change in unit-cell parameters has been observed corresponding to the change of the susceptibility around 60 K. It is possible to calculate overlap integrals between the BEDT-TTF molecules by using low-temperature crystal data. They show characteristic changes among three temperatures 300, 120, and 20 K.

Low temperature structures of (BEDT-TTF)(3)CuBr4 査読

M Watanabe, Y Nogami, K Oshima, J Yamaura, T Enoki, G Saito

SYNTHETIC METALS 86 ( 1-3 ) 1983 - 1984 1997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：ELSEVIER SCIENCE SA LAUSANNE

Single crystal X-ray structure analyses and calculation of overlap integrals for (BEDT-TTF)(3)CuBr4 reveal an occurrence of structural trimerization among BEDT-TTF molecules below Te = 60.2 K. A possible relation between this structural change and the magnetic susceptibility decrement below Tc is discussed.

DOI： 10.1016/S0379-6779(97)80988-5

Single crystal X-ray study of pressure-induced metal-insulator transition in (DMeDCNQI)(2)Cu 査読

Y Nogami, T Date, K Oshima, O Arimoto

SYNTHETIC METALS 86 ( 1-3 ) 2073 - 2074 1997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：ELSEVIER SCIENCE SA

The structures of the metallic and the insulating phases of (DMeDCNQI)(2)CU were solved under pressures of up to 15.8 kbar at room temperature. An angle a representing the deformation of CuN4 tetrahedron around the Cu atom increases almost linearly with pressure at the rate of about 0.6 deg./kbar. Furthermore, an X-ray diffuse scattering study revealed the presence of a 3 c CDW superlattice structure above 12 kbar in the high pressure insulating phase.

DOI： 10.1016/S0379-6779(97)81033-8

Characteristic SDW and FISDW behavior in (DMET-TSeF)(2)X system 査読

K Oshima, H Okuno, H Fujimura, Y Nogami, S Aonuma, R Kato

SYNTHETIC METALS 86 ( 1-3 ) 1965 - 1966 1997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：ELSEVIER SCIENCE SA LAUSANNE

The quasi one-dimensional system (DMET-TSeF)2X which is similar to (TMTSF)2X is studied. The remarkable magnetic and transport properties for the salts with X=AuI2, AuBr2 and AuCl2 are shown. It is shown from the magnetic measurement that the AuBr2 salt becomes SDW at ambient pressure and its easy-axis is along the most conducting a-axis. FISDW states has been observed for X=AuCl2 AuI2 at ambient pressure and X=AuBr2 under pressure respectively. Low temperature structural analyses have confirmed no superstructure to exist for the AuI2 and AuCl2 salts. Hall effect measurements have revealed the sign change of the Hall voltage(AuI2) and the plateau-like Hall voltage(AuCl2), but at the higher fields than those reported for TMTSF system.

DOI： 10.1016/S0379-6779(97)80980-0

A new highly conductive BO-(MeO)(2)TCNQ Langmuir-Blodgett film 査読

K Ogasawara, T Ishiguro, S Horiuchi, H Yamochi, G Saito, Y Nogami

SYNTHETIC METALS 86 ( 1-3 ) 1835 - 1836 1997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：ELSEVIER SCIENCE SA LAUSANNE

A stable, highly conductive Langmuir-Blodgett (LB) film was developed with a charge-transfer (CT) complex of bisethylenedioxytetrathiafulvalene (BO) and dimethoxytetracyanoquinodimethane using the unique nature of BO molecules. The metallic temperature dependence of electrical conductivity was observed down to 180 K, showing a maximum of 13 S/cm, The X-ray diffraction measurements show the presence of three kinds of domains corresponding to CT complex, icosanoic acid and disordered CT complex regions, The behavior of macroscopic electrical conductivity is understood well by a percolation model consisting of metallic, semiconducting and insulating sites.

DOI： 10.1016/S0379-6779(97)80927-7

Percolation conduction in BO-C(10)TCNQ conductive Langmuir-Blodgett films 査読

K Ogasawara, T Ishiguro, S Horiuchi, H Yamochi, G Saito, Y Nogami

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 58 ( 1 ) 39 - 49 1997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：PERGAMON-ELSEVIER SCIENCE LTD

The structure and electronic properties of the conductive Langmuir-Blodgett film consisting of bis(ethylenedioxy)tetrathiafluvalene- decyltetracyanoquinodimethane (BO-C(10)TCNQ) and icosanoic acid (IA) have been studied through the measurements of electrical conductivity, X-ray diffraction and electron spin resonance for samples with different mixing ration of BO-C(10)TCNQ to IA. The X-ray diffraction and ESR measurements indicate the coexistence of metallic, semiconducting and insulating domains. The temperature dependences of the electrical conductivity are reproduced by the calculation based on a modified two-dimensional percolation model consisting of three kinds of sites and their characteristics are understood well by the related phase diagram. Copyright (C) 1996 Elsevier Science Ltd

DOI： 10.1016/S0022-3697(96)00098-4

Structural phase transition in (BEDT-TTF)(3)CuBr4 at 60 K 査読

M Watanabe, Y Nogami, K Oshima, JI Yamaura, T Enoki, G Saito

SOLID STATE COMMUNICATIONS 100 ( 11 ) 755 - 758 1996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：PERGAMON-ELSEVIER SCIENCE LTD

Low temperature X-ray diffraction study for organic semiconductor (BEDT-TTF)(3)CuBr4 revealed structural phase transition from P2(1)/c to Pc by losing inversion and screw symmetries at 60.2 K where the magnetic susceptibility shows a steep decrease. Abrupt changes in (0k0) X-ray reflection intensity and lattice parameters proved that this phase transition has first-order nature. Structure analysis at 65.9 K verified that the average coordination number of Br around Cu is four. Copyright (C) 1996 Elsevier Science Ltd

DOI： 10.1016/S0038-1098(96)00512-1

Structural study of the highly conductive tridecylmethylammonium-Au(dmit)(2) Langmuir-Blodgett films 査読

H Matsuzaki, K Ogasawara, T Ishiguro, Y Nogami, M Taoda, H Tachibana, M Matsumoto, T Nakamura

SYNTHETIC METALS 74 ( 3 ) 251 - 255 1995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 LAUSANNE

The structure of the conductive Langmuir-Blodgett (LB) film consisting of tridecylmethylammonium-Au(dmit)(2) (3C10-Au) and arachidic acid is studied by the X-ray diffraction method and atomic force microscopy (AFM). The electrochemically ClO4--doped film is found to possess four phases with different interlayer spacings by the X-ray diffraction method. The intralayer molecular arrangement is found for the 3C10-Au matrix by AFM.

DOI： 10.1016/0379-6779(95)03376-U

STRUCTURAL STUDY OF NEUTRAL-IONIC TRANSITION IN DMTTF-CA 査読

Y NOGAMI, M TAODA, K OSHIMA, S AOKI, T NAKAYAMA, A MIURA

SYNTHETIC METALS 70 ( 1-3 ) 1219 - 1220 1995年3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

Dimethyltetrathiafulvalene-p-chloranil (DMTTF-CA), showing a particular neutral(N)-ionic(I) transition from a N phase into a N-I coexisting phase by cooling, was structural analyzed by X-ray at 29K, 48K, 109K and 293K Below Tc or 65K, changes observed in unit cell parameters, bond lengths and anisotropic temperature factors indicate 1) a increase in degree of charge transfer(CT) from a DMTTF donor to a CA acceptor and 2) a formation of a molecular dimerization, in I part of the coexisting phase. A possible staging superlattice was not observed.

TEMPERATURE-DEPENDENCE OF LOCAL-STRUCTURE OF RB3C60 SUPERCONDUCTOR 査読

T FUJIMOTO, Y KUBOZONO, H MAEDA, S EMURA, H ISHIDA, K OSHIMA, K KATO, S KASHINO, H YAMAZAKI, T ISHII, Y NOGAMI

FULLERENE SCIENCE AND TECHNOLOGY 3 ( 1 ) 69 - 77 1995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：MARCEL DEKKER INC

EXAFS studies on Rb3C60 are made as a function of temperature from 6 K to 300 K. It is found that the distance r(Rb-C) and the second, third and fourth cumulant terms of Debye-Waller factors, sigma(2), sigma(c)(3) and sigma(c)(4), show the anomalous behavior near T-c.

DOI： 10.1080/153638X9508545734

LOCAL-STRUCTURE OF METAL-IONS IN ARACHIDATE LANGMUIR-BLODGETT-FILM 査読

S TAKEUCHI, Y NOGAMI, T ISHIGURO, H OYANAGI

THIN SOLID FILMS 250 ( 1-2 ) 243 - 248 1994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 LAUSANNE

The fluorescence extended X-ray absorption fine structures near the Ba-L(3) edge of a Ba-arachidate (CH3(CH2)(18)COO2Ba) Langmuir-Blodgett film are investigated by using polarized X-rays from a synchrotron radiation source. From the analysis of the observed spectra for different incident angles, the absorption-site geometries are obtained. The distance from the Ba ion to the nearest neighbor oxygen atoms, lying almost in the Ba plane, is found to be 0.278 nm. Taking account of the reported structural data, a local structure model around the Ba ion is proposed.

RECENT STRUCTURAL INVESTIGATIONS OF METALLIC POLYMERS 査読

JP POUGET, Z OBLAKOWSKI, Y NOGAMI, PA ALBOUY, M LARIDJANI, EJ OH, Y MIN, AG MACDIARMID, J TSUKAMOTO, T ISHIGURO, AJ EPSTEIN

SYNTHETIC METALS 65 ( 2-3 ) 131 - 140 1994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 SCIENCE SA LAUSANNE

Recent structural studies of the undoped and iodine-doped polyacetylenes (prepared by the Tsukamoto and co-workers method), PF6--doped polypyrrole and polyaniline emeraldine base and (hydrochloric acid and camphorsulfonic acid) salts are presented. Some key features of the polymer chain array and its evolution with the conditions of preparation are emphasized. Special attention has been devoted to characterization of the various sources of structural disorder in the relationship with high conductivity and related properties exhibited by these three families of polymers. Variation in the structural order in both crystalline and amorphous regions correlates directly with the electrical and optical properties of the metallic state.

DOI： 10.1016/0379-6779(94)90174-0

LOW-TEMPERATURE MAGNETORESISTANCE OF HIGHLY CONDUCTIVE POLYACETYLENE 査読

H KANEKO, Y NOGAMI, T ISHIGURO

PHYSICA B 194 1327 - 1328 1994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：ELSEVIER SCIENCE BV

Low temperature resistivity of highly conductive iodine-doped polyacetylene changes systematically from metallic to nonmetallic with increase of disorder. The negative magnetoresistance in metallic region is ascribed to the effect of weak localization. Meanwhile the positive magnetoresistance found in nonmetallic region is explained by magnetic field effect to variable range hopping among localized states in a quasi 1D electron gas.

DOI： 10.1016/0921-4526(94)90993-8

OBSERVATION OF PHONON STOP BAND IN LANGMUIR-BLODGETT MULTILAYER FILM 査読

S TAKEUCHI, Y NOGAMI, T ISHIGURO

PHYSICA B 194 473 - 474 1994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：ELSEVIER SCIENCE BV

Using superconducting tunnel junctions, phonon transmission for Langmuir-Blodgett (LB) multilayer has been studied spectroscopically. A film with 9 layers of Cd arachidate is formed on a sapphire substrate which passes longitudinal phonon as focusing mode. We find a pronounced decrease in transmission centering 420 GHz corresponding to phonon stop band.

DOI： 10.1016/0921-4526(94)90566-5

STRUCTURE OF HIGHLY CONDUCTING PF6--DOPED POLYPYRROLE 査読

Y NOGAMI, JP POUGET, T ISHIGURO

SYNTHETIC METALS 62 ( 3 ) 257 - 263 1994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：ELSEVIER SCIENCE SA LAUSANNE

The structure of highly conducting PF6--doped polypyrrole, the room-temperature conductivity of which is approximately 1500 S/cm, is studied using X-ray 'monochromatic' Laue photographic methods. The 'crystalline' domain size along the polymer chain is estimated to be less than 20 angstrom, while adjacent chains are rather well ordered with spacing of 3.4 angstrom, suggesting that the system can be of two-dimensional nature. The influence of the structural properties on the high electrical conductivity is discussed.

SUPERLATTICE STRUCTURAL TRANSITION IN THE ORGANIC SUPERCONDUCTOR KAPPA-(BEDT-TTF)(2)CU[N(CN)(2)]BR 査読

Y NOGAMI, JP POUGET, H ITO, T ISHIGURO, G SAITO

SOLID STATE COMMUNICATIONS 89 ( 2 ) 113 - 116 1994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：PERGAMON-ELSEVIER SCIENCE LTD

By the X-ray ''monochromatic'' Laue photographic method, we observe the formation below 200 K of superlattice reflections in k-(BEDT-TTF)(2)Cu[N(CN)(2)]Br which exhibits the highest superconducting critical temperature at ambient pressure (T-c similar to 11.6 K) among the organic superconductors. This displacive structural transition doubles the lattice parameter along c. We discuss the driving force of this instability and the consequences of this structural transition on the electronic and lattice properties of this salt.

低次元物質の相転移

野上由夫

日本結晶学会誌 36 ( 0 ) 17 - 18 1994年

HIGH-RESOLUTION X-RAY STUDY ON ANOMALOUS DIFFRACTION PEAK SHIFT IN DIMERIZED LANGMUIR-BLODGETT SUPERLATTICE FILMS 査読

Y NOGAMI, K OGASAWARA, S TAKEUCHI, T ISHIGURO, T NAKAJIMA, K OHSUMI, Y SHIMIZUGAWA

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 62 ( 9 ) 3114 - 3126 1993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：PHYSICAL SOC JAPAN

Structures of Langmuir-Blodgett (LB) superlattice films formed with alternately deposited fatty acid Cd salts with different alkyl-chain length are studied by high resolution X-ray diffraction method using a synchrotron radiation source. The remarkable diffraction peak shift is observed in the superlattice film. The shift is interpreted in terms of the Guinier effect in partially-disordered superlattice system. Simultaneous modulation of molecular position and of molecular scattering factor results in the peak shift. The effect of alkyl-chain species substitution and of cooling on the peak shift are also described. The partial disorder in the superlattice is caused by dissolution of LB film.

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