Structural studies of ceramic small crystals by synchrotron X-ray diffraction

同步加速器X射线衍射研究陶瓷小晶体的结构

基本信息

批准号：
11450245
负责人：
ISHIZAWA Nobuo
金额：
$ 9.41万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

The present study has been carried out with the objective to determine accurate and precise structures of functionally important crystals in various ambient circumstances, e.g., various temperatures, pressures, magnetic fields, electrostatic fields, and humidity. Such analyzes using the single crystal diffraction technique have so far been suffered from the extinction effect which often reduces the incident intensity expected from the kinematical theory. The present study seems to have succeeded in eliminating the problem from practical point of view, by the use of small crystal of about 10 micrometer in size and by the use of the synchrotron source with high flux. The results obtained are determination of incommensurately modulated structures in various inorganic solid solution, investigation of the superstructures of layered perovskites, LiCa2Nb3O10, LiCa2Ta3O10, RbCa2Nb3O10, RbCa2Ta3O10, NaCa2Nb3O10, NaCa2Ta3O10, HCa2Nb3O10, HCa2Ta3O10, SrMgF4, BaMgF4 and so forth. All these studies were done at the Photon Factory, High-Energy Physics Laboratory, Japan, and at the principal investigator's laboratory using the imaging-plate three-circle diffractometer which has been recently developed for the rapid data collection at ambient conditions. The principal investigator now bears in mind a thought that this project has successfully conducted by the group members and the results have contributed to the scientific communities involved in the materials science and crystallography to a great extent.

本研究的目的是为了确定在各种环境环境中，例如各种温度，压力，磁场，静电场和湿度的精确和精确结构。迄今为止，使用单晶衍射技术进行了这种分析，其灭绝效应通常会降低运动学理论所期望的入射强度。从实际的角度，通过使用约10微米的小晶体和使用具有高通量的同步子源，本研究似乎已经成功地消除了问题。 The results obtained are determination of incommensurately modulated structures in various inorganic solid solution, investigation of the superstructures of layered perovskites, LiCa2Nb3O10, LiCa2Ta3O10, RbCa2Nb3O10, RbCa2Ta3O10, NaCa2Nb3O10, NaCa2Ta3O10, HCa2Nb3O10, HCA2TA3O10，SRMGF4，BAMGF4等。所有这些研究均在日本的光子厂，高能物理实验室以及主要研究者的实验室使用成像板的三环衍射仪进行，该衍射仪最近在环境条件下为快速数据收集而开发。现在，首席研究人员牢记了该项目已成功进行的想法，结果在很大程度上为参与材料科学和晶体学参与的科学社区做出了贡献。