学会誌「高圧力の科学と技術」
Rev. High Pressure Sci. Technol.

Vol.10  No.3 (2000) Abstract


特集−分子性固体−
Rev. High Pressure Sci. Technol. 10-3,187-193(2000)
Li の圧力誘起構造相転移の圧力誘起構造相転移
Phase Transition of Li under High Pressure
森 嘉久  財部 健一
Yoshihisa MORI  Kenichi TAKARABE
Lithium starts to lose its high reflectivity at 19 GPa and turns black like graphite. The color change is reversible Lithium starts to lose its high reflectivity at 19 GPa and turns black like graphite. The color change is reversible with large hysteresis. The black color does not change to 200 GPa. At 75 GPa, it is not transparent to visible with large hysteresis. The black color does not change to 200 GPa. At 75 GPa, it is not transparent to visible light, nor to a laser beam at 0.785 eV, nor to a laser beam at 0.12 eV. This behavior means it is either a semicon- light, nor to a laser beam at 0.785 eV, nor to a laser beam at 0.12 eV. This behavior means it is either a semicon-ductor with a gap below 0.12 eV, or a semi-metal like graphite although such behavior could arise from multi- ductor with a gap below 0.12 eV, or a semi-metal like graphite although such behavior could arise from multi-internal reflections as a result of the anisotropy of the permittivity in the single crystal. There is no vibron peak internal reflections as a result of the anisotropy of the permittivity in the single crystal. There is no vibron peak from a lithium molecule up to 150 GPa. The Raman spectrum at 160 GPa has a broad peak around 600 cm from a lithium molecule up to 150 GPa. The Raman spectrum at 160 GPa has a broad peak around 600 cm-1 on a on a large background, which is considered to be caused by the fluorescence of diamond. large background, which is considered to be caused by the fluorescence of diamond.

[Lithium, phase transition, molecular solid, DAC, Raman scattering Lithium, phase transition, molecular solid, DAC, Raman scattering]
〒700-0005 岡山理科大学理学部基礎理学科岡山理科大学理学部基礎理学科
 Department of Applied Science, Okayama Univrsity of Science, Ridai 1-1, Okayama 700-0005



特集−分子性固体−
Rev. High Pressure Sci. Technol. 10-3,194-199(2000)
酸素の金属化と超伝導
Metallization and Superconductivity in Oxygen under High Pressure
清水克哉
Katsuya SHIMIZU
Oxygen is popular but unique among diatomic molecules in that it behaves magnetically at low temperature.Under high pressure, however, we expect the insulator-metal transition. This expectation has been suggested by measuring its optical reflectivity[1] under high pressures around 95 GPa (1 Mbar). A new structural transition[2] is considered to be accompanied by metallization. Obviously, the most direct method of detecting metallization is to measure the electrical resistance. We measured the resistance of oxygen at pressures of over 100 GPa[3] and identified the metallic state from a change in the slope of dR/dT . In this paper, we present our findings on the superconducting transition of oxygen under high pressures of around 100 GPa and at temperatures of under 0.6 K. The superconducting transition is indicated by a drop in resistance. We confirmed this by observing the magnetic field dependence of the drop and by detecting the Meissner demagnetization signal.

[oxygen, diatomic molecule, high pressure, metallization, molecular dissociation, superconductivity,electrical resistance]
〒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
Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama, Toyonaka, Osaka 560-8531



特集−分子性固体−
Rev. High Pressure Sci. Technol. 10-3,200-207(2000)
固体CX4(X=H, F, Cl)の圧力誘起構造相転移
Pressure-induced Structural Phase Transition of CX4(X = H, F, Cl) Solid
川村春樹 赤浜裕一
Haruki KAWAMURA Yuichi AKAHAMA
A molecular solid consisting of low-Z elements tends to crystallize into a plastic crystal, in which molecules rotate freely on lattice points. By the application of pressure, rotation of molecules freezes and the order-disorder transition takes place. The structural phase transition of these molecular crystals has been frequently studied by spectrographic techniques. The recent progress of synchrotron radiation sources has enabled us to investigate crystal structures of low-Z materials through x-ray diffraction analysis. In this article, pressure-induced structural phase transition of CX4 (X = H, F, Cl) solids is reviewed.

[molecular crystal, plastic crystal, phase transition, x-ray diffraction, Raman spectrum]
〒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
Faculty of Science, Himeji Institute of Technology, 3-2-1 Kouto, Kamigori, Ako-gun, Hyogo 678-1297



特集−分子性固体−
Rev. High Pressure Sci. Technol. 10-3,208-213(2000)
ヨウ化スズの高圧力下における構造相転移
Phase Transition in Tintetraiodide at High Pressure
佐藤 恭子  浜谷 望
Kyoko SATO  Nozomu HAMAYA
High-pressure studies of tintetraiodide SnI4 are reviewed. Recent x-ray diffraction study has shown that SnI4 undergoes successive phase transition from an insulator crystalline phase (I ;Pa3 ) to a metallic crystalline phase (II) at 7 GPa, to the amorphous state at about 15 GPa, and to a non-molecular crystalline phase (III ;Fm3m) at 61 GPa. The crystal structure of phase III has been determined to be substitutional disordered structure in which both iodine and tin atoms are randomly located at the fcc sites.

[tintetraiodide, metallization, amorphization, molecular dissociation]
〒112-8610 東京都文京区大塚2-1-1 お茶の水女子大学大学院 人間文化研究科 複合領域科学専攻
Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1, Ohtsuka, Bunkyo-ku, Tokyo 112-8610



特集−分子性固体−
Rev. High Pressure Sci. Technol. 10-3,214-220(2000)
高圧下における C6I6 の結晶および分子構造
Crystal Structure and Molecular Structure of C6I6 under High Pressure
中山敦子 藤久裕司 青木勝敏
Atsuko NAKAYAMA Hiroshi FUJIHISA Katsutoshi AOKI
Hexaiodobenzene (C6I6) is one of the organic monomolecular crystals indicating pressure-induced metallization. Our recent studies on x-ray powder diffraction experiments and Raman scattering spectral measurements of C6I6 under high pressure are reviewed: pressurization in a preliminary process of the pressure-induced metallization causes six iodine atoms to be suspended from a benzene-ring accompanied by a decrease in intermolecular I-I distances. It follows from this that charge transfer interaction is mainly generated by the overlapping of a 5pz orbital of iodine and a π-orbital of carbon among the adjacent molecules which accelerates the molecular deformation.

[hexaiodobenznen, pressure-induced metallization, x-ray powder diffraction, Raman spectroscopy, Fermi resonance]
〒305-8565 茨城県つくば市東1-1 物質工学工業技術研究所 極限反応部 高圧化学グループ
National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305-8565



解説
Rev. High Pressure Sci. Technol. 10-3,221-227(2000)
液体リンの1次相転移
A First-Order Phase Transition in Liquid Phosphorus
片山芳則
Yoshinori KATAYAMA
In this article, a recent discovery of a liquid-liquid phase transition in phosphorus is reviewed. By an in situ X-ray diffraction method, we have observed an abrupt pressure-induced structural change between a low-pressure molecular liquid and a high-pressure polymeric liquid at about 1 GPa. Experimental results strongly support that it is a first-order transition between two thermodynamically stable liquid phases. This is the first in-situ observation of such a transition in a liquid of pure substance.

[phosphorus, liquid-liquid transition, diffraction, synchrotron radiation, pressure]
〒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 放射光科学研究センター
Synchrotron Radiation Research Center, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148, Japan



解説
Rev. High Pressure Sci. Technol. 10-3,228-234(2000)
高圧下でのX線を用いた構造解析と格子振動解析
Structure and Lattice Vibration Analyses under High Pressure
using X-ray Diffraction and X-ray Absorption Techniques
吉朝 朗
Akira YOSHIASA
The single-crystal x-ray diffraction method using a diamond anvil cell is an important method for crystal structure determination under high-pressure. The x-ray absorption spectroscopy under high-pressure provides the detailed information on local structure around particular kinds of atoms, even if the crystal structure is unknown. Extended x-ray absorption fine structure (EXAFS) spectroscopy is useful as a probe of vibration dynamics under pressure. An anharmonic effective pair potential can be investigated using the EXAFS technique. The knowledge of the local structure is of primary importance for the understanding of the complicated physical properties of solid solutions. The change of the spin state of the Co4+ ion in the perovskite-type Sr(Co, Mn)O3 solid solution whose magnetic properties varies according to the compositions have been explained based on the local structure analysis.

[x-ray diffraction method, x-ray absorption spectroscopy, XANES, EXAFS, structure determination, local structure, effective pair potential, lattice vibration, solid solution, spin state]
〒560-0043 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 Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka 560-0043



解説
Rev. High Pressure Sci. Technol. 10-3,235-242(2000)
高圧力実験装置入門−光学窓(金属ガスケットシール法)−
A Guide for High Pressure Experements
−Optical Window ( Metal Gasket Method )−
網田富士嗣・梶本興亜
Fujitsugu AMITA  Okitsugu KAJIMOTO
The effective and reliable sealing with metal gaskets for a high-pressure optical window is described. A practical method for polishing a window plug is explained. We have developed a pair of jigs to shape Au gaskets, which are explained in detail. The shaping of Au gaskets with the jigs is also demonstrated. A window plug gripping jigs to fasten the high-pressure optical window is also introduced.

[high-pressure optical window, metal gasket]
〒606-8502 京都市左京区北白川追分町 京都大学大学院理学研究科化学専攻
Division of Chemistry, Graduated School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502



実験ワンポイント
Rev. High Pressure Sci. Technol. 10-3,243-244(2000)
氷の準安定融解曲線の測定
Measurement of the Metastable Melting Curves of Ice Phases
三島 修
Osamu MISHIMA
We have developed an experimental method using emulsions to measure the metastable melting curves of ice phases at low temperatures and high pressures. For the melting experiment, we constructed a special hydraulic press with two oil-pressure systems, and reduced error in the sample pressure.

[high pressure, pressure control, melting, phase transition, liquid water, ice]
〒305-0044 つくば市並木 1-1 科学技術庁無機材質研究所
National Institute for Research in Inorganic Materials, 1-1 Namiki, Tsukuba 305-0044




〒606-0805
京都市左京区下鴨森本町 15 (財)生産開発科学研究所内
日本高圧力学会事務局
Tel (075)721-0376 Fax (075)723-9629
koatsu@mbox.kyoto-inet.or.jp