Abstract

The phenomenological mechanisms for increasing the unipolarity under thermal processing in the short-circuiting conditions for heavily doped LiNbO₃:ZnO crystals are analyzed by comparing with the temperature behavior of nominally pure LiNbO₃:ZnO crystals with the congruent composition. It is shown that an increase in the unipolarity and, hence, the disappearance of the domain structure in heavily doped LiNbO₃:ZnO crystals is initiated by thermal decomposition of charged polar clusters stabilizing domain walls. The decomposition of polar clusters is accompanied with an abrupt jumpwise injection of extra charge carriers (Li⁺ cations). As a result, the conductivity of LiNbO₃:ZnO crystals at a temperature above 800 K is an order of magnitude higher than that of nominally pure LiNbO₃ crystals with the congruent composition. This leads to the degradation of the domain structure in LiNbO₃:ZnO crystals in contrast to LiNbO₃ crystals with the congruent composition.

中文翻译：

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重掺杂LiNbO 3：ZnO晶体热处理过程中单极性变化的机理

摘要

通过与标称纯的具有相同组成的LiNbO ₃：ZnO晶体的温度行为进行比较，分析了在短路条件下重掺杂LiNbO ₃：ZnO晶体在短路条件下提高热处理过程中单极性的现象机理。结果表明，单极性的增加以及因此在重掺杂的LiNbO ₃：ZnO晶体中畴结构的消失是由稳定畴壁的带电极性簇的热分解引发的。极性簇的分解伴随着额外电荷载体（Li ⁺阳离子）的突然跳跃式注入。结果，LiNbO ₃的电导率：在高于800 K的温度下，ZnO晶体比组成完全一致的标称纯LiNbO ₃晶体高一个数量级。与组成一致的LiNbO ₃晶体相比，这导致LiNbO ₃：ZnO晶体的畴结构退化。