| Co-Investigator(Kenkyū-buntansha) |
NAGAI Takaya Graduate School of Science, Osaka University Research Associate, 大学院・理学研究科, 助手 (20243131)
YOSHIASA Akira Graduate School of Science, Osaka University Associate Prof., 大学院・理学研究科, 助教授 (00191536)
TSUNEMI Hiroshi Graduate School of Science, Osaka University Professor, 大学院・理学研究科, 教授 (90116062)
|
|---|
| Research Abstract |
The aim of the present research project aimed to investigate the structure changes and stability relations of earth's interiors under the conditions of same temperature and pressure as carth mantle and core. Dynamical structure changes under compression were observed by time-resolved diffraction experiment in time interval of second or millisecond. In order to understand the mechanism of phase transition or decomposition, we developed the single-crystal X-ray diffraction system for kinetic studies of these structure transformations. For this purpose, two-dimensional X-ray detector of charge coupled detector (CCD) was planed to be installed in the newly devised system. It enables to execute the time-resolved study. After searching the several CCD detectors made by SIMENS, NONIUS, QUANTUM and RIGAKU.The RIGAKU detector was tested from the viewpoints of dynamic range, quantum efficiency, positional resolution and reproducibility. Computer programs for driving the system and data analysis
… More
were also developed. Combined with the rotating anode X-ray generator and HUBER four-circle diffractometer facilitated in laboratory, diamond anvil high-pressure cell with electric resistance heater makes possible the diffraction study of structure transformation in the process of compression. The high-pressure and high-temperature studies up to 80GPa and 550℃ can be possible.
The present instrumental development has already been reported in annual meeting of High-Pressure Technology and Sciences : By using the new system the following experiments are scheduled in near future.
(1) Observation of pressure-induced amorphization, martensic structure transition, and precursor phenomenon of melting.
(2) Time-resolving diffraction study of structure transformation including dehydration, degas, phase decomposition, radiation damage etc.
(3) Inspection of crystallization from melts.
(4) Perception of solid-solid reaction under compression with heating condition.
(5) Elucidation of electronic density of state in the filed of material sciences, metallurgy, solid-state physics and several other science.
The present detector system combined with synchrotron radiation will be an effective tool for kinetic study of structure transformation. Less
|
