(1-x)(Mg(0.7)Zn(0.3))TiO3-xCa(0.61)La(0.26)TiO3系陶瓷的微波介电性能研究(英文)

Studies on the (1-x)(Mg_(0.7)Zn_(0.3))TiO_3-xCa_(0.61)La_(0.26)TiO_3 Microwave Dielectric Ceramics System

本实验研究了(1-x)(Mg0.7Zn0.3)TiO3-x(Ca0.61La0.26)TiO3(MZT-CLT)系陶瓷的微观结构和微波介电性能,通过(Ca0.61La0.26)TiO3来协调(Mg0.7Zn0.3)TiO3陶瓷的谐振频率温度系数.MZT-CLT陶瓷的主晶相为(Mg0.7Zn0.3)TiO3,第二相为Ca0.61La0.26TiO3和(Mg0.7Zn0.3)Ti2O5.烧结温度和陶瓷组成对微波介电性能影响显著,当烧结温度为1275℃时,可以获得良好的致密度,当烧结温度超过1300℃时,Zn的蒸发导致陶瓷致密度和介电性能下降.随着(Ca0.61La0.26)TiO3含量的增大,材料的介电常数增大,品质因数减小.当x=0.13,烧结温度为1275℃保温4h,(MZT-CLT)陶瓷具有优良微波介电性能,εr=26,Q.f=86000 GHz,τf=-6×10-6/℃.

The microstructures and the microwave dielectric properties of the（1-x）（Mg0.7Zn0.3）TiO3-xCa0.61La0.26TiO3（MZT-CLT） ceramic system were investigated.The objective of the present work is to compensate for the negative temperature coefficient of resonant frequency of（Mg0.7Zn0.3）TiO3 by the addition of（Ca0.61La0.26）TiO3.MZT-CLT ce-ramics exhibited mixed phases of（Mg0.7Zn0.3）TiO3 as the main phase associated with minor phases of Ca0.61La0.26TiO3 and（Mg0.7Zn0.3）Ti2O5.The microwave dielectric properties are strongly correlated with the sintering temperature and the composition.Very dense MZT-CLT ceramics were synthesized by sintering at 1275℃.When the samples were sintered at temperatures above 1300℃,the evaporation of Zn resulted the decrease in density and degradation in di-electric properties.With the increasing of x,the relative dielectric constant（εr） of the ceramics increases and the prod-uct of quality factor and resonant frequency（Q.f） decreases.The εr,Q.f and temperature coefficient of resonant fre-quency（τf） of 0.87（Mg0.7Zn0.3）TiO3-0.13Ca0.61La0.26TiO3 ceramic sintered at 1275℃ are 26,86000 GHz and -6×10-6/℃,respectively.