Er_2O_3掺杂对BaTiO_3陶瓷介电性能的影响

Effects of Er_2O_3 Dopant on Dielectric Properties of BaTiO_3 Ceramics

采用溶胶-凝胶法制备了掺杂Er2O3的BaTiO3陶瓷。测试结果表明,掺杂Er2O3能降低BaTiO3陶瓷的电阻率,且在开始时其电阻率随着掺杂量的增大而升高,在掺杂x(Er2O3)=0.003(摩尔分数)时电阻率最高,然后随掺杂量的升高而降低,在掺杂x(Er2O3)=0.007时电阻率最低,从纯BaTiO3陶瓷的2.6 TΩ.m下降为18 GΩ.m,此变化规律有异于La,Ce,Nd,Sm等稀土元素掺杂的规律。掺杂Er2O3使BaTiO3陶瓷的介电性能发生明显变化,掺杂x(Er2O3)为0.001和0.002时,可改善BaTiO3陶瓷的介电性能和频率特性,具有较好的频率稳定性。掺杂Er2O3使BaTiO3陶瓷的居里温度升高为130.9℃,交流电导随着温度的升高而增大,并在居里温度点附近达到最大。

BaTiO3 ceramics doped with various qualities of Er2O3 were prepared （the additive mol fraction were 0.001, 0.002, 0.003, 0.005, 0.007 respectively） through Sol-Gel method. Their resistivity at room temperature and the dielectric properties were researched. It is found that the addition of Er2O3 can make the resistivity of BaTiO3 ceramics decline. The resistivity increases with increase in Er2P3 additive mol fraction at first and reaches the highest at 0. 003 , and then begins to decrease, when the Er2O3 additive mol fraction is 0. 007, the resistivity is the smallest, which declines from 2. 6 TΩ· m to 18 GΩ· m, this rule is different from that of La, Ce, Nd, Sm dopant. The addition of Er2O3 also can make the dielectric properties of BaTiO3 ceramics change evidently under different additive mol fraction and different frequency. When the additive mol fraction of Er2O3 is 0. 001 and 0. 002, the dielectric properties and the frequency characteristics are improved obviously. The Curie-temperature increases to 130.9 ℃ by addition of Er2O3. The alternating conductance increases with the change of temperature, and reaches the highest at the Curie-temperature.