固体电解质La_（1－x）Ca_xF_（3－x）的阻抗谱研究

STUDY ON IMPEDANCE SPECTRUM OF SOLID ELECTROLYTE La_(1-x)Ca_xF_(3-x)

在４２３～７７３Ｋ温度范围内利用阻抗谱测定了多晶固体电解质Ｌａ＿（１－ｘ）Ｃａ＿ｘＦ＿（３－ｘ）（ｘ＝０．０１，０．０３，０．０５，０．０７，０．０９）的电导率随ＣａＦ＿２含量的变化及其在不同温度区间的表现电导激活能。结果表明，掺入１％～９％（ｍｏｌ）ＣａＦ＿２的ＬａＦ＿３其电导率比ＬａＦ＿３单晶有很大提高（１０倍左右），其电导率数量级在１０￣（－４）～１０￣（－２）Ｓ·ｃｍ￣（－１）之间，其中Ｌａ＿（０．９５）Ｃａ＿（０．０５）Ｆ＿（２．９５）具有最高的电导率。

Ionic conductivities of polycrystalline solid electrolyte La_(1-x)Ca_xF_(3-x) with x=0 01,0. 03 ,0.05,0. 07 and 0 09 respectively were measured by the impedance spectroscopy technique in a range of temperaturefrom 423 to 773 K. The relationship between the ionic conductivities and the composition of La_(1-x)Ca_xF_(3-x) wasstudied.The apparent conductive activation energy at different temperatures was obtained. The results indicatethat the ionic conductivity of the polycrystalline LaF_3 doped with CaF_2 1% to 9%(in mole content),is 10 timeshigher than that of LaF_3 single crystal. The conductivity is in the range of order from 10￣(-4) to 10￣(-2) S·cm￣(-1).La_(0.95)Ca_(0.05)F_(2. 95) has the maximum conductivity. The effect of composition and temperature on conductivity is dis-cussed also.