ZnAl_2O_4和La_2O_3对Ca_(0.61)Nd_(0.26)TiO_3-MgTiO_3复合陶瓷介电性能的影响

通过传统的固相反应合成掺杂ZnAl_2O_4和La~(3+)(来自La_2O_3)的Ca_(0.61)Nd_(0.26)TiO_3-MgTiO_3复合陶瓷粉体,干压成型后在空气气氛下常压烧结制备ZnAl_2O_4和La~(3+)掺杂Ca_(0.61)Nd_(0.26)TiO_3-MgTiO_3复合陶瓷样品。分别研究了La~(3+)和ZnAl_2O_4的掺杂量对复合陶瓷样品的微观形貌、相组成和介电性能的影响。结果表明:ZnAl_2O_4具有细化晶粒的作用;Ca_(0.61)Nd_(0.26)TiO_3-MgTiO_3复合陶瓷样品的致密度随La~(3+)和ZnAl_2O_4含量的增加而增加;介电常数和谐振频率温度系数随ZnAl_2O_4含量的增加而减小,随La_2O_3添加量变化不大;品质因数值随ZnAl_2O_4含量的增加先增加后减小。制备出的ZnAl_2O_4和La~(3+)掺杂Ca_(0.61)Nd_(0.26)TiO_3-MgTiO_3复合陶瓷致密度达到94%以上,介电常数在40~50之间,谐振频率温度系数小于40×10~(-6)℃~(-1),品质因数大于38 000GHz,可以用于通信技术领域。

Effects of ZnAl2O4 and La2O3 on dielectric properties of Ca0.61 Nd0.26 TiO3-MgTiO3 composite ceramics

ZnAl2 O4 and La3+ (from La2 O3) doped Ca0.61 Nd0.26 TiO3-MgTiO3 powders were synthesized by solid state reaction method,which were used for preparing ZnAl2 O4 and La3+ doped Ca0.61 Nd0.26 TiO3-MgTiO3 composite ceramics through dry-pressing and sintering in air atmosphere.The effects of doping contents of La3+ and ZnAl2 O4 on the microstructure,phase formation and dielectric properties performance of the composite ceramics were investigated.The results show that ZnAl2O4 additive can adjust the crystallite size,so the density of the sintered ceramics increases with the increase of La3+ and ZnAl2O4 contents.The dielectric constant and temperature coefficient of the composite ceramics decrease with the increase of ZnAl2 O4 content,but are not significantly affected by the La3+ content.The quality factor of the composite ceramics increases first and then decrease with the increase of ZnAl2O4 content.The obtained composite ceramics with a sintered density above 94％ displays good dielectric properties,such as dielectric constant is about 40-50,temperature coefficient is less than 40)× 10-6 ℃C-1 and quality factor is larger than 38 000 GHz.Thus ZnAl2 O4 and La3+ doped Ca0.61 Nd0.26 TiO3-MgTiO3 composite ceramics can be used in the field of communication technology.