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

• 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
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450245/
• 关键词: small single crystal; synchrotron X-ray diffraction; imaging plate diffractometer; electron density distribution; layered perovskite; crystal chemistry; superstructure; 放射光回折; ニオブ酸リチウム; 層状ペロブスカイト; 電子密度分布解析

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.

本研究的目的是确定具有重要功能的晶体在各种环境条件下（例如各种温度、压力、磁场、静电场和湿度）的准确和精确的结构。迄今为止，使用单晶衍射技术的此类分析一直受到消光效应的影响，消光效应通常会降低运动学理论预期的入射强度。本研究通过使用尺寸约10微米的小晶体以及使用高通量的同步加速器源，从实用的角度来看似乎已经成功地解决了这个问题。获得的结果是确定各种无机固溶体中的不通约调制结构，研究层状钙钛矿的超结构，LiCa2Nb3O10、LiCa2Ta3O10、RbCa2Nb3O10、RbCa2Ta3O10、NaCa2Nb3O10、NaCa2Ta3O10、HCa2Nb3O10、 HCa2Ta3O10、SrMgF4、BaMgF4 等。所有这些研究都是在日本高能物理实验室光子工厂和主要研究者的实验室中使用最近开发的成像板三圆衍射仪进行的，该衍射仪用于在环境条件下快速收集数据。首席研究员现在牢记这样一个想法：该项目由小组成员成功实施，其结果在很大程度上为涉及材料科学和晶体学的科学界做出了贡献。

项目成果

Y.Tabira: "Annular dynamical disorder of the rare earth ions in a La_2zr_2O_7pyrochlore via single crystal synchrotoron X-ray diffraction"Zeitschrift fur Kristallographie. 216[2]. 92-98 (2001)

Y.Tabira：“通过单晶同步旋转 X 射线衍射分析 La_2zr_2O_7 烧绿石中稀土离子的环形动力学紊乱”Zeitschrift Fur Kristallographie。

B. E. Etschmann et al.: "A synchrotron X-ray Study of the Electron Density in Er_3Al_5O_<12> and Yb_3Al_5O_<12> Garnets"Acta Crystallographica. B57. 136-141 (2001)

B. E. Etschmann 等人：“Er_3Al_5O_<12> 和 Yb_3Al_5O_<12> 石榴石中电子密度的同步加速器 X 射线研究”晶体学报。

S.Kuze: "Charge Density Study of MnS_2 by Synchrotron X-ray Diffraction and DVXα method-"Bulletin of the Society for Discrete Variational Xα. 13[1]. 46-50 (2000)

S.Kuze：“通过同步加速器 X 射线衍射和 DVXα 方法进行 MnS_2 的电荷密度研究 -”离散变分协会通报 Xα 13[1]。

Barbara Etschmann: "A Synchrotron X-ray Diffraction Analysis of Near-Stoichiometric LiNbO3"Zertschrift fur Kristallographie. 216[8]. 455-461 (2001)

Barbara Etschmann：“近化学计量 LiNbO3 的同步加速器 X 射线衍射分析”Zertschrift Fur Kristallographie。

B.E.Etschmann: "A synchrotron XRD study of a small congruent LiNbO_3 crystal : a compatible approach to power diffraction"Powder Diffraction. 16[2]. 81-85 (2001)

B.E.Etschmann：“小型全等 LiNbO_3 晶体的同步加速器 XRD 研究：功率衍射的兼容方法”粉末衍射。