掺杂Nb_2O_5及MgO对细晶BaTiO_3系统介电性能影响的研究

Study on Effect of Nb_2O_5 and MgO on Fine-Grained BaTiO_3 Ceramics

研究了Nb2 O5和MgO掺杂对细晶BaTiO3陶瓷介电性能的影响。Nb2 O5的加入可以有效地抑制BaTiO3陶瓷晶粒的长大 ,可使陶瓷的平均粒径减少至 0 8μm左右 ,从而改善了陶瓷的介电性能 ;添加适量的MgO不但展宽了居里峰 ,而且防止晶粒过渡生长 ,并拓宽了陶瓷的烧结温度区 ;有效地控制Nb/Mg的摩尔比可获得良好的材料系统性能参数 ,使ε≥ 4 60 0 ,tgδ≤ 1 2 % ,△C/C≤± 1 5 %。

Effect of doping Nb_2O_5 and MgO on the fine-grained BaTiO_3 based ceramics was studied.In this system,the grain growth could be inhibited effectively by Nb_2O_5,so that the average grain size of ceramics was decreased (about 0.8 μm),and the dielectric properties of the ceramics were improved.By doping with MgO,the peak value at Curie temperature could be outspread,the abnormal growth of the grain size could be prevented and the range of sintering temperature could be widen. The good properties of ceramics could be obtained by propely controlling mole ratio of Nb/Mg,of which ε is≥4600,tgδ≤1.2%,△C/C≤±15%.