Development of High-Pressuire X-ray Structure Analysis Technique and Solid State Chemistry at High Pressure

压力是固体物理性质研究中最重要的参数之一。通常，高压下单晶的结构和电阻率的精确数据是用夹持式高压室获得的。但是在夹持式电池中可以达到的最大压力并不是很高(在使用铍圆柱电池进行X射线研究的情况下)。最大压力约为10kbar)。虽然钻石镶嵌。这是最方便的高压发生器，允许我们在更高的压力下进行实验。在非常脆弱的有机单晶上应用金刚石加压技术是非常困难的。本研究项目的目的是利用金刚石衬底和成像板X射线探测器对有机晶体进行高压X射线结构分析。还发展了高压单晶四探针电阻率测量技术，以促进高压下软分子材料的固态科学研究。我们最近成功地获得了一种有机导体的高压晶体结构，其精度从未实现过。此外，我们还利用改进的高压单晶电阻测量方法，首次发现了第一个有机超导体类硫化合物的超导转变。

Pressure is one of the most important parameters in the studies of physical properties of solids. Usually the precise data on the structure and electrical resistivities of single crystals at high pressure have been obtained by using clamp-type high-pressure cell. But the maximum pressure attainable in the clamp-type cell is not so high (in the case of X-ray studies using Be-cylinder cells. the maximum pressure is about 10kbar). Although the diamond anvile. which is the most convenient high-pressure generator, permits us the experiments at higher pressure. it is very difficult to apply the diamond-anvile high-pressure technique to very fragile organic single crystals. The aim of the present research project was the development of high-pressure X-ray structure analysis on the organic crystals by using diamond anvile and imaging plate X-ray detector. The technique of high-pressure single crystal four-probe resistivity measurements has been also developed in order to contribute to advance the solid state science of soft molecular materials at high pressure. We have recently succeeded to obtain the high-pressure crystal structure of an organic conductor whose accuracy has never realized. Furthermore, we have found the superconducting transition of the sulfur-analog of the first organic superconductor for the first time by using the improved method of high-pressure single crystal resisitivity measurements.