Electrical properties in semiconducting BaTiOィイD23ィエD2 bicrystals

BaTiO-D23-D2， Which is often used as based materials for electroceramics， exhibits semiconduction when it is doped with cations whose valence is large than host cations' valence。在一般情况下，大多数电子学在实践中被有效地用于实际用途，而在多晶体及其电子性质中与其谷物边界现象经常密切相关。因此，它必须是必要的，直接在单一谷物边界上调查电气性质。在这一研究中，BaTio-D23-D2 bicrystals were fabricated and then their electric properties were examined。以下的结果可能会被发现。（1） It was succeeded in construction of the technique for controlling the abnormal grain growth in BaTiO D23 y D2 by changing A/B-site ratio。圆锥状颗粒结构，具有大约1毫米的颗粒大小，可以获得。（2） It was found that the electrical properties in BaTiOイD23イエD2 bicrystal closely depend on the grain orientation relationship。The Magnitude of Positive Temperature Coefficient of Resistance effect decerases with an increase in the coherency at grain boundaries。（3） The similar tendency could be obtained also in SrTiO D23イエD2 bicrystal， which has the same lattice structure and similar electrical properties。

BaTiOィイD23ィエD2, Which is often used as based materials for electroceramics, exhibits semiconduction when it is doped with cations whose valence is large than host cations' valence. In general, most of electroceramics are utilized for practical use as in polycrystals and their electrical properties is often closely related to their grain boundary phenomena. Therefore, it must be necessary to investigate the electrical properties directly at single grain boundaries. In this study, BaTiOィイD23ィエD2 bicrystals were fabricated and then their electrical properties were examined. The following results could be obtained.(1) It was succeeded in construction of the technique for controlling the abnormal grain growth in BaTiOィイD23ィエD2 by changing A/B-site ratio. Coarse-grained structure with a grain size of about 1mm could be obtained.(2) It was found that the electrical properties in BaTiOィイD23ィエD2 bicrystal closely depend on the grain orientation relationship. The magnitude of Positive temperature coefficient of resistivity effect decerases with an increase in the coherency at grain boundaries.(3) The similar tendency could be obtained also in SrTiOィイD23ィエD2 bicrystal, which has the same lattice structure and similar electrical properties.