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

SnO_2-TiO_2二元体系是公认的具有绝对固溶体和独立分解特征的层状结构体系。这种相分离有望在纳米尺度上形成不同相之间具有连贯和清洁界面的自组织结构。在本研究中，为了同时控制微观结构和电学性能，在体系中掺杂了三价Fe^<3+>离子。通过实验工作，首次揭示了无需退火即可成功获得具有周期性有序结构特征的自组织相分离。通过对二元氧化体系的热力学控制，使其具有了特有的相分离微观结构和性能。因此，本材料设计对于开发新型的纳米异质结构陶瓷复合材料是有益的和可期待的。

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.