高圧力の科学と技術
Online ISSN : 1348-1940
Print ISSN : 0917-639X
14 巻 , 3 号
- Ultra High Pressure Fluid Reaction -
選択された号の論文の9件中1~9を表示しています
特集-超高圧流体反応-
  • 木村 正樹
    2004 年 14 巻 3 号 p. 218-224
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    Ultrasound velocities of He and Ne were measured up to 3.0 and 3.7 GPa, respectively, at 295 K. Ultrasound velocities of Ar, Kr and Xe were measured up to solidification pressures at room temperature. The phenomena of phase separation and solidification in the systems of He-Kr, He-Ar, Ne-Ar and He-CO2 were investigated by sound velocities and optical methods. Phase diagrams of He-Kr and He-CO2 were represented by those methods. Solidification curves of He-Ar and Ne-Ar were obtained at 295 K.
  • 鈴木 敏弘, 高橋 栄一, 仲井 伯享, 鈴木 一也, 竹田 一夫, 西本 武雄
    2004 年 14 巻 3 号 p. 225-229
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    An 850 MPa type internally-heated gas pressure vessel, which adopts a double-stage compression system, was newly installed at the Tokyo Institute of Technology. At second compressing stage of this instrument, pressure gauge is difficult to use and pressure is estimated from the loaded oil pressure. In order to acquire reliable pressure conditions, a manganin string was placed in the sample chamber and its electrical resistance was measured as a pressure sensor. By using this technique, uncertainty of pressure value for the sample chamber is decreased to a few MPa.
  • 小野 重明
    2004 年 14 巻 3 号 p. 230-234
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    The effect of pressure and temperature on the dihedral angles of aqueous fluid in silicate rock matrix was reviewed. A connectivity of aqueous fluid at high-pressures and high-temperatures is important to understand the distribution and migration of super critical water in the Earth's mantle. The change of dihedral angles is due to both the P-T conditions and the solubility of silicate components into aqueous fluid.
  • 川本 竜彦
    2004 年 14 巻 3 号 p. 235-241
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    A series of direct observation of complete miscibility between aqueous fluids and island arc andesite/rhyolite magmas has been conducted using modified Bassett's type externally heated diamond anvil cell. The critical phenomena are observed between aqueous fluids and Fuji 1707 magmas with chemical compositions from andesite (62 wt.% SiO2) to rhyolite (69% SiO2). Such critical phenomena between aqueous fluids and magmas equilibrated with mantle peridotite system remain uncertain. This study is the first observation of critical phenomena of natural andesite and rhyolite with aqueous fluids, suggesting a second critical point between magmas and aqueous fluids in the depths of the Earth. Such a supercritical fluid can be separated into a melt and a fluid eventually along its migration to the surface. Under such circumstances elemental fractionation between the aqueous fluid and the melt should take place.
  • 井上 徹
    2004 年 14 巻 3 号 p. 242-247
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    Water is the most abundant volatile component on the Earth's surface, and it is important to clarify the water distribution in the Earth's interior because water influences the physical properties and melting temperature of minerals. Here the author reviews our recent works about the H2O partitioning among high-pressure polymorphs of olivine. Based on the partitioning results combining with the seismological constraint, the author discusses the amount of water distribution in the Earth's interior.
  • 遊佐 斉
    2004 年 14 巻 3 号 p. 248-252
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    Nitridation of III-group elements is performed by high-pressure nitrogen fluid in a laser-heated diamond anvil cell to synthesize III-nitrides up to 15 GPa. In this article, we approach the nitridation process of elements through a close-up on the recovered products by high resolution scanning electron microscopy, Raman microscopy and micro-focused X-ray diffractometry. Gallium nitride (GaN) and aluminum nitride (AlN) are recrystallized as wruzite type structure followed by dissolution of gallium and aluminum into oversaturated nitrogen fluid. On the other hand, boron can be changed to cubic boron nitride (BN) without an extensive dissolution into nitrogen fluid. It would be considered that the difference of crystal habits is derived from the degree of dissolubility which would be partly related to the melting point of elements.
  • 長谷川 正, 八木 健彦
    2004 年 14 巻 3 号 p. 253-259
    発行日: 2004年
    公開日: 2004/12/10
    ジャーナル フリー
    Synthesis of metal nitrides has been tried in a supercritical nitrogen fluid at high pressures (about 10 GPa) and high temperatures yield using diamond anvil cell and YAG laser heating system. Transition-metal nitrides such as TiN, VN, Fe2N, ZrN, NbN, MoN and HfN can be easily synthesized by a direct nitriding reaction between metal and fluid nitrogen. Superconducting transition of TiN, VN, ZrN and NbN can be observed using one synthesized sample by a SQUID magnetometer. Colorless transparent fine crystals of GaN in the wultz-rock type structure can be also grown from gallium and fluid nitrogen. They have hexagonal platelet or prismatic morphology, indicating a solution growth using supercritical nitrogen fluid as a solvent. These results in this study open us a new way of synthesis and crystal growth of various kinds of nitrides in a supercritical nitrogen fluid under high temperatures and high pressures yield using diamond anvil cell and YAG laser heating.
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