16:00-16:30
Higher-dimensional crystallography in materials research
Dr. Yuichi Michiue(QBC, Synchrotron X-ray Group)
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In the field of materials science there is an incentive to develop new methods to analyze complex structures. Higher-dimensional crystallography, or the superspace formalism, was originally developed for the analyses of aperiodic structures. The method is also applied to superstructures (commensurately modulated structures) and long-period structures. In this talk, the basic principles of the method are briefly explained. Then, advantages of the superspace formalism are shown taking a few examples in my recent works, such as new transparent conducting oxides Ga2O3(ZnO)m (m: integer). The compounds are treated as composite crystals, or compositely modulated structures. A unified description for the phases belonging to the series is presented using a structure model in (3+1) dimensional superspace.