掺杂MgO对Ba_(0.8)Sr_(0.2)TiO_3陶瓷介电性的调制

MgO doping modulation on dielectric properties of Ba_(0.8)Sr_(0.2)TiO_3 ceramics

采用溶胶凝胶法制备了Ba_(0.8)Sr_(0.2)TiO_3陶瓷粉末,通过固相掺杂的方式,利用传统陶瓷制备工艺制备了MgO掺杂的Ba_(0.8)Sr_(0.2)TiO_3陶瓷,研究了MgO的掺杂量对Ba_(0.8)Sr_(0.2)TiO_3陶瓷结构及晶粒尺寸的影响,研究了MgO的掺杂量对Ba_(0.8)Sr_(0.2)TiO_3陶瓷的介电性、铁电性的影响.在此基础上讨论了MgO掺杂Ba_(0.8)Sr_(0.2)TiO_3陶瓷结构与电学性能的内在相关性.研究结果表明,MgO的掺杂量可显著影响Ba_(0.8)Sr_(0.2)TiO_3陶瓷的居里温度,以及介电常数随温度的变化特性,随着MgO掺杂量的增加,介电常数随温度的非线性变化范围逐渐减小,并且陶瓷的击穿强度会增加,介电损耗会减少.说明适当的MgO掺杂可改善Ba_(0.8)Sr_(0.2)TiO_3陶瓷的介电性,调制Ba_(0.8)Sr_(0.2)TiO_3陶瓷的介电性的非线性.

Ba_（0.8）Sr_（0.2）TiO_3 ceramicpowders was prepared by sol-gel method. MgO-doped Ba_（0.8）Sr_（0.2）TiO_3 ceramics were prepared by solidstatedoping method. The effects of MgO doping content on the microstructure and electric properties,especially on dielectric and ferroelectric properties were investigated experimentally. The correlation of structure and electrical properties of Ba_（0.8）Sr_（0.2）TiO_3-x% MgO ceramics was discussed. The results show that MgO doping contents significantly affect the Curie temperature and the dielectric response characteristics. MgO is beneficial to increase the breakdown strength and improve the temperature stability of dielectric properties of Ba_（0.8）Sr_（0.2）TiO_3 ceramics. It demonstrates that appropriate MgO doping can improve Ba_（0.8）Sr_（0.2）TiO_3 ceramics dielectric,modulating the dielectric nonlinearity of Ba_（0.8）Sr_（0.2）TiO_3 ceramics.