New mechanism of ionic conductivity in hydrogen-bonded crystals M3H(XO4)2 [M=Rb, Cs, X=S, Se]
New mechanism of ionic conductivity in hydrogen-bonded crystals M3H(XO4)2 [M=Rb, Cs, X=S, Se]
复制标题
氢键晶体 M3H(XO4)2 [M=Rb, Cs, X=S, Se] 离子电导率的新机制
DOI：
10.1143/jpsj.67.1999
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发表时间：
1998
影响因子：
1.7
通讯作者：
H. Kamimura
中科院分区：
文献类型：
--
作者：
Takuo Itô;H. Kamimura
提出了M3 H（XO 4）2 [M=Rb，Cs，X=S，Se]型晶体高温准弹性相离子导电机理的模型。传导机制的主要特点如下：（1）H2 XO 4（+e）和XO 4（-e）两种缺陷态是通过氢键的断裂而热形成的，（2）H2 XO 4（+e）缺陷态和XO 4（-e）缺陷态缺陷态从XO 4四面体相干移动到远处的XO 4，这是氢键间质子连续隧穿的结果。分别用递推方法和久保公式计算了这些缺陷态相干运动的态密度和迁移率。态密度显示了贝特晶格的特征，即，在铁弹转变温度下，电导率为10 - 3 Ω-1cm-1量级，与实验结果一致.
A model for the mechanism of ionic conductivity in the high temperature paraelastic phase of M 3 H(XO 4 ) 2 [M=Rb, Cs, X=S, Se] type crystals is proposed. The key features of the conduction mechanism are the following; (1) two kinds of defect states, H 2 XO 4 (+e) and XO 4 (-e) , are formed thermally by breaking of a hydrogen-bond, (2) the H 2 XO 4 (+e) defect state and the XO 4 (-e) defect state move coherently from an XO 4 tetrahedron to a distant XO 4 as the result of successive proton tunneling among hydrogen-bonds. The density of states and the mobility are calculated for the coherent motions of these defect states by the recursion method and the Kubo formula, respectively. The density of states shows the characteristic feature of the Bethe lattice, i.e., the twin peak structure due to self-similarity, while the conductivity is obtained as an order of a magnitude of 10 -3 Ω -1 cm -1 at the ferroelastic transition temperature, consistent with experiments.