Nd3+A位置换对(Pb0.5Ca0.5)(Fe0.5Nb0.5)O3陶瓷微波介电性能的影响

研究了Nd3+离子A位置换改性(Pb0.5Ca0.5)(Fe0.5Nb0.5)O3陶瓷的微波介电性能.(Pb0.5Ca0.5)1-xNdx](Fe0.5Nb0.5)O3(PCNFN)陶瓷的微波介电性能得到改善是由于少量过剩的Nd3+与(Pb,Ca)2+的固溶能够消除氧空位.当x=0.02时,能够形成单相的钙钛矿相,随着Nd3+置换量的增加,过剩的Nd3+将导致第二相焦绿石的形成,焦绿石会恶化PCNFN的微波介电性能.PCNFN介电性能随x的增加而下降是由于焦绿石相随x增加的结果.当x=0.02-0.05,PCNFN陶瓷有很好的微波介电性能,介电常数K>100,Qf值为5385-5797GHz,频率温度系数TCF随Nd3+含量的增加从正的变为负的.

Effect of A-site Substitution by Nd~3+ on the Microwave Dielectric Properties of (Pb0.5Ca0.5)(Fe0.5Nb0.5)O3 Ceramics

Microwave dielectric properties of A-site substitution by Nd3+ in(Pb0.5Ca0.5)(Fe0.5 Nb0.5)O3 system were investigated. Microwave dielectric properties of (Pb0.5Ca0.5)1-xNdx](Fe0.5 Nb0.5)O3 (PCNFN) were improved because the solid solution of small amount of surplus Nd3+ with (Pb,Ca)2+ could eliminate oxygen vacancies. A single perovskite phase was formed when x=0.02. Surplus Nd3+ resulted in the formation of secondary phase (pyrochlore), which can deteriorate to the microwave dielectric properties of PCNFN ceramics. The decreasing of dielectric properties with x content was mainly caused by the formation of pyrochlore. Dielectric constant was above 100 and quality factor Qf values were 5385-5797GHz as x = 0.02 -0.05. Temperature coefficient of resonant frequency (TCF) was changed from positive to negative with the increase of x content.