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

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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.