| Co-Investigator(Kenkyū-buntansha) |
STVELTSON V. University of Western Australia, 結晶学センター, 講師
SCHMID S. Australian National University, 化学研究所, 研究員
THOMPSON J.G. Australian National University, 化学研究所, 研究員
田平 泰規 日本大学, 文理学部, 助手 (80272722)
丸茂 文幸 日本大学, 文理学部, 教授 (10013492)
VAALSTA T.P. University of Western Australia
MASLEN E.N. University of Western Australia
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| Research Abstract |
The present study has been carried out with the objective to determine modulated structures and electron densities of functional inorganic materials using synchrotron radiations. The precise analysis using the single crystal diffraction technique has 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 (a) determination of incommensurately modulated structure in the Ta_2O_5-WO_3, solid solution, (b) determination of the structure of Mg_6SO_2(OH)_<14> needle-shaped tiny crystals which can not be grown more than 100 micron in length and several micron in width, (c) electron density measurements on SmFeO_3, YFeO_3, HoFeO_3, C-type rare-earth sesquioxides, Y_2BaCuO_5 superconduction-related compound, LaOCl layred-type structure, LiNbO_3 and LiTaO_3 optoelectronic materials, a synthetic mineral of ferrian aluminian diopside, cobalt-containing olivine, (d) determination of compositely modulated structure of Nb_2Zr_<X-2>O_<2X-1> with x=8, (e) development of a fast X-ray counter using the avalanche-photo-diodes, etc. All these studies were done at the Photon Factory, High-Energy Physics Laboratory (KEK), Japan, in most cases, using the horizontal-type four-circle diffractometer at the beamline 14A.The head 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.
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