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在室温至 16 0℃范围内测量了掺钇钨酸铅 (PWO∶Y)晶体的直流电导率 ,证明此时的载流子为极化子 .观察到极化子由能带导电到跳跃导电转变引起的电导率极小 .在此温区的交流导纳分析给出的交流电导率比直流电导率大三个数量级 ,说明此时的交流电导率主要是复介电常数的贡献 .当样品的电导率和介电常数均随频率而变化时 ,从交流测量只能得到样品的总的导纳谱 ,而不能将其中的电导谱和介电谱分开 .
The direct current conductance of the yttrium-doped lead tungstate (PWO: Y) crystal was measured at room temperature to 160 ° C, and the carrier at this time was proved to be a polaron.It was observed that the polaron was changed from band-to-band conductivity The conductivity induced by the transition is very small.An AC admittance analysis given in this temperature region is three orders of magnitude larger than the DC conductivity, indicating that the AC conductivity at this time is mainly the contribution of the complex permittivity.When the sample Of the conductivity and permittivity both vary with frequency, only the total admittance spectrum of the sample can be obtained from the AC measurement, and the conductance and dielectric spectra therein can not be separated.