新型铌酸盐基介质材料的制备及性能评价

Preparation and Performance Evaluation of New Niobate Based Dielectric Materials

为了降低铌酸盐基微波介质材料的烧结温度,以Cu O、ZnO和Nb2O5为主要原料,采用固态反应合成法制备了一种新型铌酸盐基介质材料,通过XRD和SEM扫描电镜对其进行了表征,并评价了介质材料的体密度、相对密度和介电性能。结果表明:当烧结温度由820℃升高至920℃时,新型铌酸盐基介质材料的物相组成和微观形貌均会发生明显变化,并且烧结温度越高,介质材料的晶格参数a、b、c和Vuint就越大。介质材料的体密度和相对密度同样随着烧结温度的升高而逐渐增大,当烧结温度达到920℃时,体密度和相对密度分别为5.945g·cm-3和97.15%。此外,随着烧结温度的不断升高,介质材料的介电常数εr值逐渐增大,介质损耗Q×f先增大后减小,谐振频率温度系数τf值逐渐减小。当烧结温度为900℃时,制备的新型铌酸盐基介质材料具有良好的介电性能,εr值为23.551 F·m^(-1),Q×f值为24 200 GHz,τf值为-3.16×10^(-5)℃^(-1)。

In order to reduce the sintering temperature of niobate based microwave dielectric materials, a new type of niobate based dielectric materials was prepared by solid state reaction synthesis with CuO, ZnO and Nb2O5as the main raw materials. It was characterized by XRD and SEM.And the bulk density, relative density and dielectric properties of the dielectric materials were evaluated. The results showed that when the sintering temperature rose from 820 ℃ to 920 ℃, the phase composition and micro morphology of the new niobate based dielectric materials changed significantly, and the higher the sintering temperature, the larger the lattice parameters a, b, c and Vuint of the dielectric materials. The bulk density and relative density of dielectric materials also increased with the increase of sintering temperature. When the sintering temperature reached 920 ℃, the bulk density and relative density were 5.945 g·cm-3and 97.15% respectively. In addition, with the increasing of sintering temperature, the dielectric constant of dielectric materials gradually increased, and the dielectric loss first increased and then decreased, temperature coefficient of resonant frequency value decreased gradually. When the sintering temperature was 900 ℃, the new niobate based dielectric materials had good dielectric properties, εr value was 23.551 F·m^(-1), Q×f value was 24 200 GHz, τf value was-3.16 ×10^(-5)℃^(-1).