Simultaneous Control of Oxide Semiconductor Hetero-interface and Electrical Properties via Self-organized Phase Separation

SnO_2-TiO_2二元体系具有绝对固溶体和调幅分解的特征片层结构。这样的相分离有望在纳米尺度上形成自组织结构，不同相之间的界面是一致的和干净的。在本研究中，为了同时控制系统的微结构和电学性能，在系统中掺杂了三价的Fe~(2+)和Fe~(2+)离子。通过实验首次发现，在不进行任何热处理的情况下，可以成功地获得具有周期性有序结构特征的自组织相分离。由于二元氧化物体系的热力学控制，导致了二元氧化物体系特有的相分离组织和性能。因此，本文的材料设计对开发具有纳米级异质结构的新型陶瓷复合材料是有用的和可望的。

SnO_2-TiO_2 binary system is well known to exhibit an absolute solid solution and spinodal decomposition with characteristic lamellar structure. Such a phase separation is expected to forms self-organized structure with coherent and clean interface between different phases in nanometer scale. In this study, trivalent Fe^<3+> ion was doped to the system in order to control the both microstructures and electrical properties simultaneously. Through the experimental work, it was firstly revealed that self-organized phase-separation with characteristic periodic ordered-structure could be successfully obtained for the as-sintered samples without any annealing. The characteristic phase-separated microstructures and properties by doping to the binary oxide system was caused by the thermodynamical control of the system. It is thus concluded that the present materials design is useful and expectable to develop new-type of ceramic composite with nano-scaled hetero-structures.