EFFECT OF La2O3 DOPING ON DIELECTRIC PROPERTIES OF BaZr0.1Ti0.9O3CERAMICS BY SOL-GEL METHOD

Abstract

Lanthanum doped BaZr0.1Ti0.9O3 (BZT10) dielectric ceramics were prepared by sol-gel method using barium acetate, zirconia nitrate, butyl titanate and La2O3, etc, as raw materials and La2O3 as dopant, the effects of La2O3 doping on dielectric properties of BaZr0.1Ti0.9O3 ceramics are also investigated. The XRD results show that the crystal structure for BZT10 ceramics is a single perovskite structure, and the admixture of La3 + does not generate new phase. With the increase of La2O3 content, the grain size decreases continuously when the doping amount x ≤ 0.5 mol%, when the doping amount x > 0.5 mol%, the grain size basically remains unchanged, and the grain size is uniform. With the La2O3 content increasing, the dielectric constant rises at first and then decreases for the samples sintered at 1280 oC, 1300 oC and 1330 oC, when the sintering temperature is 1280 oC and the La2O3 doping amount is x = 0.7 mol%, the dielectric constant is the largest. It can also be seen that the dielectric loss of La3+ -doped sample is lower than that of the blank sample in the temperature range from room temperature to 125 C. In the terms of dielectric constant, dissipation factor and temperature stability for dielectric loss, the trace amount of La3+ doping could influence the dielectric properties remarkably