掺杂Sm_2O_3对BaSrTiO_3介电陶瓷性能的影响

Effects of Sm_2O_3 doping on the dielectric properties of BaSrTiO_3 ceramics

以碳酸钡、碳酸锶和二氧化钛等为原料,Sm2O3为掺杂剂,制备了BaSrTiO3系介质陶瓷。利用SEM等仪器研究了陶瓷试样的微观形貌和介电性能。结果表明:当Sm2O3掺杂量低于0.10%摩尔分数时,Sm3+进入晶格A位;但随着Sm2O3掺杂量的增加,Sm3+越来越倾向于进入晶格B位。在Sm2O3掺杂量为摩尔分数0.10%时,BaSrTiO3陶瓷的相对介电常数达到最高值4800;随着Sm2O3掺杂量继续增加,陶瓷的介电损耗逐渐降低,最低降至0.0070。

Sm2O3-doped BaSrTiO3 dielectric ceramics were prepared with BaCO3, SrCO3 and TiO2 as raw materials. The micromorphology and dielectric properties of the prepared ceramics were studied. The results show that Sm3＋ occupies the A-site of the perovskite lattice when the amount of Sm2O3 is less than 0.1% （mole fraction）. However, when the Sm2O3 content is above 0.1%（mole fraction）, Sm3＋ tends to occupy the B-site. The relative permittivity of BaSrTiO3 ceramics reaches its maximum value of 4 800 when 0.1%（mole fraction） Sm2O3 is doped. And, the dielectric loss of BaSrTiO3 ceramics decreases remarkably with further increase in the Sm2O3 content and reaches its minimum value of 0.007 0 when the content of Sm2O3 is 0.8% （mole fraction）.