Anomalous ultrasonic absorption in solid state ionic conductor

在KNa1.4Zr1.3Mg0.7 (PO4) 3和Na2.4Zr1.3Mg0.7 (PO4) 3之间制备了具有NASICON型结构的Na_yK1_<-y>Na1.4Zr1.3OMgo0.7 (PO4) 3固溶体。阳离子取代提高了电导率，在y=0.7时达到最大值。每种化合物的活化能均由阿伦尼乌斯图求得，且随y的变化基本不变。通过x射线衍射得到了六方参数a和c。a参数相当恒定，b对y的非线性行为。这些结果与结构特征和电导率数据相关。pbbr2 - cur的固溶体在150℃以上具有较高的导电性。在x=0.01 ~ 0.3的浓度下，研究了复介电常数与频率和温度的关系。它们表现出由离子电导引起的强介电弛豫。在30 ~ 200ºC的温度范围内测量了超声波吸收。根据浓度的不同，它们在170℃左右表现出明显的峰值。利用德拜弛豫，过量吸收被解释为铜离子在两个位点之间的跃迁。

Solid solution Na_yK1_<-y>Na1.4Zr1.3OMgo0.7 (PO4) 3 was prepared between KNa1.4Zr1.3Mg0.7 (PO4) 3 and Na2.4Zr1.3Mg0.7 (PO4) 3 with NASICON type structure. Cationic subsitution improved the conductivity which reached a maximum for y=0.7. For each compositions, the activation energy was obtained from th Arrhenius plots, and showed fairly constant against y. Hexagonal parameters a and c were obtained by X-ray diffraction. The a parameter was fairly constant and the b nonlinear behavior against y. These results are correlated with structural features and conductivity data. The solid solution of PbBr2-CuBr has a high electric conductivity above 150ﾟC.The frequency and temperature dependences of complex dielectric constants have been investigated in the concentration of x=0.01-0.3. They exhibited a strong dielectric relaxation caused by the ionic conducrion. Ultrasonic absorption has been measured in the temperature range from 30 to 200ﾟC.They showed a distinct peak at about 170ﾟC depending on the concentration. Using the Debye relaxation, the excess absorption was explained as transition of copper ions between two sites.