Ca掺杂钨镁酸铅陶瓷材料的制备及其介电性能

研究了Ca掺杂钨镁酸铅(PMW)陶瓷材料的合成、结构、烧结以及介电性能。结果发现：在Ca^2 摩尔分数小于15％时，能形成单相的PCMW钙铁矿相，结构由原来的斜方相向立方相转变。用二步合成法制备的样品容易致密烧结，气孔率比一步法制备的样品小。Ca的加入降低了材料的介电损耗，在频率为1MHz时，介质损耗达到了10^-4。当Ca^2 摩尔分数大于10％时，材料的Curie峰宽化显著，介电常数温度系数降低。

PREPARATION AND DIELECTRIC PROPERTIES OF Ca-DOPED LEAD MAGNESIUM TUNGSTATE CERAMICS

Preparation method, crystal structure, sinterability and dielectric properties of Ca_doped lead magnesium tungstate (PMW) ceramics were investigated. The results show that the single phase perovskite structure of PCMW formed when molar fraction of Ca 2 was less than 15%, and the structure changed from orthorhombic to cubic. Samples prepared by two_step method form higher relative density and lower porosity than those prepared by one_step method. The addition of Ca 2 can decrease the dielectric loss, the order of which can reach 10 -4 at 1 MHz. As the molar fraction of doped Ca 2 is greater than 10%, the Curie peak is apparently broadened and the temperature coefficient of dielectric constant is decreased.