PbO过量对大各向异性改性PbTiO_3性能的影响

Effects of PbO excess on modified PbTiO_3 ceramics with large anisotropy

研究了一种新型的具有大各向异性的改性PbTiO3 陶瓷材料的性能随着材料制备中铅过量的变化而变化的关系 ,其中包括材料的机电耦合系数、机械品质因素、介电损耗等 .研究结果表明当铅过量为 1%～ 2 % (摩尔百分比 )时 ,材料的性能达到较佳 .通过分析认为 :当铅不足时 ,主要是由其它的B位掺杂离子取代A位的铅 ,从而造成配方B位离子的重新排列 ,材料的性能因而有所下降 ;当铅过量时 ,铅离子将取代A位的钙 ,部分钙离子将进入晶界 。

The relationships of PbO excess with the properties of an new modified PbTiO 3 ceramics with large anisotropy were investigated, the performances including the electromechanical coupling factors, mechanical quality factor, dielectric loss and so on were studied. The results showed that the performances of the ceramics were better when the PbO excess were 1?% or 2?%. The conclusions were: when PbO are shortage, there were some substitutions mainly came from B-site would substituted in A-site, made rearrangement in B-site and thus. When PbO were excesses, the lead ions would substituted calcium in A-site, made some CaO come into inter-grains, and depressed the performances of the ceramics also.