Y~(3+)掺杂ZnO压敏陶瓷的微结构和电性能研究

摘要

Y(NO_3)_3·6H_2O-doped ZnO varistor ceramics were prepared by two-step sintering method.The effects of Y(NO_3)_3·6H_2O-doped amount on the microstructure and electric properties of ZnO varistor ceramics were systematically studied by XRD,SEM and EDX.The results show that with increasing Y(NO_3)_3·6H_2O-doped amount,voltage gradient(V_T) and nonlinear coefficient (α) increase,grain size decreases,the donor number density (N_d) and density of grain boundary states (N_s) decrease,whereas barrier width(ω) increases.When x[Y(NO_3)_3·6H_2O] and sintering temperature are 1.2% and 1 100 ℃,respectively,obtained ZnO varistor ceramics have best electric properties: voltage gradient of 675 V/mm,nonlinear coefficient of 63.9,and leakage current of 2.40 μA.%采用两步烧结法制备了Y~(3+)掺杂的(以Y(NO_3)_3·6H_2O形式加入)ZnO压敏陶瓷,通过XRD、SEM和EDX系统研究了Y~(3+)掺杂量对ZnO压敏陶瓷微结构和电性能的影响.结果表明:随着Y~(3+)掺杂量的增加,电位梯度V_T和非线性系数a 提高,晶粒尺寸减小,施主浓度N_d和晶界态密度N_s降低,势垒宽度ω增大.当掺杂的x[Y(NO_3)_3·6H_2O]为1.2%、烧结温度为1 100 ℃时,ZnO压敏陶瓷电性能最好,其V_T为675 V/mm,a为63.9,漏电流I_L为2.40 μA.