Rev. High Pressure Sci. Technol.

Vol.4  No.1(1995) Abstract

Rev. High Pressure Sci. Technol. 4-1,22-27(1995)
High-Pressure Structural Transition of Oxygen at 96 GPa: Possibility of Molecular Metal
赤浜 裕一 川村 春樹
By using high-energy and high-brilliant synchrotron radiation source in ESRF and PF, an angle-dispersive powder x-ray diffraction study on oxygen has been carried out up to 117 GPa at room temperature. A new high-pressure structural transition was observed at 96 GPa and explained as an isostructural one with a discontinuous change of lattice constants in a monoclinic cell. Metallization for oxygen reported by S. Desgreniers et al. [1] is ascribed to the transition.

[oxygen, high-pressure, phase transition, synchrotron radiation, molecular metal, x-ray diffraction]
〒678-1297 兵庫県赤穂郡上郡町光都3-2-1 姫路工業大学理学部物質科学科
Department of Material Science, Faculty of Science, Himeji Institute of Technology, 3-2-1, Kouto, Kamigohri, Hyogo 678-12

Rev. High Pressure Sci. Technol. 4-1,28-34(1995)
Structure Determination of High Pressure Phases of Bismuth by
Synchrotron Radiation Angle Dispersive Powder Diffraction
陳 久華1 岩崎 博2 亀卦川 卓美3
Chen Jiuhua, Hiroshi IWASAKI, Takumi KIKEGAWA
High quality diffraction data of high pressure phases of bismuth, Bi?V, Bi?V' and Bi?W, were obtained by using the high energy Synchrotron Radiation. Based on the observed diffraction data, crystal structures of these phases have been solved as, Bi?V: tetragonal structure with unit cell parameters of a=0.8680±0.0005nm and c=0.4248±0.0003nm at 3.2 GPa, Bi?V': the same structure as Bi?V, and Bi?W: monoclinic structure with unit cell parameters of a=0.6463±0.0005nm, b=0.6460±0.0005nm, c=0.6582±0.0006nm and γ=118.84±0.05° at 3.9 GPa and 503 K. The relations of atomic arrangements between Bi?V and Bi?X, Bi?W and Bi?X are discussed.

[in-situ X-ray diffraction, angle dispersive method, crystal structure, bismuth]
1Center for High Pressure Research and Department of Earth and Space Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794-2100, USA.
2〒525-8577 草津市野路東1-1-1 立命館大学理工学部光工学科
Faculty of Science and Engineering, Ritsumeikan University,Nogihigashi 1-1-1, Kusatsu, Shiga 525-8577
3〒305-0801 つくば市大穂1-1 高エネルギー
Photon Factory, National Laboratory for High Energy Physics, 1-1 Oho, Tsukuba, Ibaraki 305-0801.

Rev. High Pressure Sci. Technol. 4-1,35-41(1995)
Pressure-induced Amorphization of Silicates and Germanates
Takaya NAGAI
Pressure-induced amorphization is a kinetically hindered phenomenon. The amorphization has been a topic not only in the field of high pressure physics but also in the field of earth science for the last decade. The amorphization of minerals will play an important role to understand the mechanism of deep-forcus earthquakes in the subduction zone, the rheological properties of the slub and the recycling water in the mantle, and so on. In this article, the pressure-induced amorphization of silicates and germanates will be reviewed from the view point of the crystal structures and our resent experiments using the synchrotron radiation will be introduced.

[amorphization, silicates, germanates, coordination change, XAFS]
〒560-0043 大阪府豊中市待兼山町1-1 大阪大学大学院理学研究科宇宙地球科学専攻
Department of Space and Earth Science, Osaka University, 1-16 Machikaneyama, Toyonaka, Osaka 560-0043

Rev. High Pressure Sci. Technol. 4-1,42-48(1995)
XAFS Studies under Pressure
Yoshinori KATAYAMA
Recent advance in X-ray Absorption Fine Structure(XAFS) study under pressure is reviewed. After a brief introduction to XAFS and its applications to high-pressure studies, recent development of XAFS measurements under pressure at the Photon Factory is presented. We successfully obtained X-ray absorption spectra at pressures up to 10 GPa and temperatures up to 700 ℃ using a multi-anvil type apparatus, MAX90. Results of our studies on crystalline selenium, amorphous selenium and isolated selenium chains are presented.

[high pressure, XAFS, EXAFS, synchrotron radiation, crystal structure, amorphous, selenium]
〒679-5148 兵庫県佐用郡三日月町光都1-1-1 日本原子力研究所関西研究所放射光利用研究部

Rev. High Pressure Sci. Technol. 4-1,49-54(1995)
Mossbauer Spectroscopic Study
那須 三郎
Saburo NASU
Mossbauer spectroscopic studies of pressure-induced transition from antiferro- to ferro-magnetism of Fe in SrFeO3 at 74 GPa has been performed using a diamond anvil cell (DAC) and the nuclear forward scattering of synchrotron radiation under external magnetic field. Brief description of the principles in Mossbauer spectroscopy using a radio-isotope g-ray source has been given. The basic concept and a method to detect the nuclear forward scattering with synchrotron radiation have been explained briefly.

[DAC, 57Fe Mossbauer spectroscopy, iron-oxides, SrFeO3, hyperfine interaction parameters, nuclear forward scattering, synchrotron radiation, pressure-induced antiferro-to-ferromagnetic transition]
〒560-8531 豊中市待兼山町1-3 大阪大学大学院基礎工学研究科物理系専攻物性物理化学分野
Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560

Rev. High Pressure Sci. Technol. 4-1,55-61(1995)
Angle-dispersive Diffraction Measurement Using a Radial Slit
矢尾板 憲一
Kenichi YAOITA
A newly developed angle-dispersive diffraction measurement system for high-pressure experiments is reviewed. This system has an optical device called Radial Slit, which is consisted with multiple collimators aligned radially. This eliminates the diffraction from the materials surrounding the sample, so that we can measure diffraction from samples in a multi-anvil press by an imaging-plate (IP). Performance of the Radial Slit has been evaluated to be satisfactory, and diffraction patterns of crystal corundum and glassy silica have successfully been obtained using this system.

[angle-dispersive, x-ray diffraction, multi-anvil press, radial slit, imaging plate, MAX90, synchrotron radiation, high pressure]
〒196-8666 昭島市松原町3-9-12 理学電機(株)応用技術センター東京分析センター

Rev. High Pressure Sci. Technol. 4-1,62-67(1995)
Phase Transition of Microcrystals by Infrared Spectroscopy
難波 孝夫
In this article, the important role of the synchrotron radiation in the field of spectroscopic study under high pressure up to 20 GPa in the infrared region is emphasized. As a typical example of such experiments which became possible to perform, the experiment on the surface phonon of CdS microcrystals under high pressure using a DAC is presented. Through an analysis of the energy shifts of the surface phonon with pressure, we found that the magnitude of the critical pressure indicating a structural phase transition in the microcrystal differs from that for the bulk.

[synchrotron radiation, phase transition, surface phonon, microcrystal, CdS, DAC, far-infrared spectroscopy ]
〒657-8501 神戸市灘区六甲台町1-1 神戸大学大学院自然科学研究科
Kobe University, Rokkodai-cho1-1, Nada-ku, Kobe 657-8501

Rev. High Pressure Sci. Technol. 4-1,68-75(1995)
Diamond Compact
上原 一仁
Kazuhito UEHARA
Diamond compact (polycrystalline Diamond: PCD) is the material produced by sintering diamond powder under ultra-high pressure and high temperature conditions. It has been widely used as cutting tools, wire drawing dies, rock drilling bits and wear-resistant parts.
This paper describes in outline the kinds and the applications of commercial PCD, the manufacturing process, sintering mechanism and cutting performances of PCD for cutting tools and the relation between PCD and recent CVD diamond tools.

[diamond compact, PCD, ultra-high pressure, cutting tools, CVD diamond]
〒970-1144 いわき市好間工業団地11-1 東芝タンガロイ(株)いわき工場
Toshiba Tungaloy Co., Ltd.,

Rev. High Pressure Sci. Technol. 4-1,76-83(1995)
The Synthesis of Heterocyclic Compounds under High Pressure
田口 洋一  安本 昌彦
Heterocyclic compounds are used now in various fields, and many reports have been published on the synthesis of these compounds every year. This article deals with the studies in our group on the synthesis of heterocyclic compounds including sulfur or nitrogen under high pressure. Nitriles, cianamides, carbon disulfide, isocyanates, and isothiocyanates were good reagents for high pressure synthesis and led to some novel reactions different from those at ordinary pressure. The reactions of these reagents under high pressure have a possibility of developing new synthetic methods of heterocyclic compounds.

[heterocyclic compounds, cyanides, cyanamides, carbon disulfide, isocyanates, isothiocyanates]
〒305-8565 つくば市東1-1 物質工学工業技術研究所有機合成化学部有機構造相関研究室
National Institute of Materials and Chemical Research,Higashi 1-1, Tsukuba 305-8565

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