Gd_2O_3掺杂对BaTiO_3陶瓷电性能的影响

Effects of Gd_2O_3 Doping on Electric Characteristics of BaTiO_3 Ceramics

采用溶胶-凝胶法制备了掺杂不同量Gd2O3(分别为0 001、0 002、0 003、0 005、0 007mol mol)的BaTiO3陶瓷,并对其电性能进行了研究。结果表明:Gd2O3掺杂使BaTiO3陶瓷的电阻率明显下降,当添加量为0 002mol mol时,电阻率最小,为1 27×105Ω·m;晶粒电阻随着温度的变化,呈现NTC效应,而晶界电阻随着温度的变化,呈现PTC效应,而且晶界电阻远远大于晶粒电阻,说明Gd2O3掺杂BaTiO3陶瓷的PTC效应是一种晶界效应;Gd2O3掺杂使BaTiO3陶瓷的介电常数和介电损耗在低频时明显增大,在高频时又明显降低。

BaTiO3 ceramics doped with Gd2O3(the additive content was respectively 0001,0002,0003,0005,0007 mol/mol)were prepared by solgel method.Effects of Gd2O3 doping on electric characteristics of BaTiO3 ceramics were studied.The results showed that the resistivity decreased obviously with the doping of Gd2O3,and when Gd2O3 content was 0002 mol/mol,the resistivity was the smallest,namely 127×105 Ω·m.The grain resistance exhibited NTC effect,but the grain boundary resistance showed PTC effect.The grain boundary resistance was larger than the grain resistance,so the PTC effect originated from the grain boundary.The dielectric constant (ε) and the dielectric loss (tan δ) of BaTiO3 ceramic doped with Gd2O3 increased at lower frequency and decreased at higher frequency obviously.