【摘要】 以硝酸钙、硝酸镁、正硅酸乙酯为先驱体,利用溶胶-凝胶法合成(Ca_1-xMg_x)SiO₃（x=0.1、0.2、0.3、0.4、0.5）陶瓷粉体,研究了Mg²⁺取代Ca²⁺对陶瓷物相组成、烧结特性以及微波介电性能的影响规律.结果表明,Mg²⁺在CaSiO₃中的最大固溶度不超过0.2;随着Mg²⁺对Ca²⁺取代量的增加,陶瓷在烧结后的主晶相出现从CaSiO₃相向CaMgSi₂O₆相的转变,陶瓷的烧结特性及介电性能出现先增加后下降的趋势;当x=0.3时,陶瓷体中CaSiO₃相与CaMgSi₂O₆相共存,克服了单相CaSiO₃或CaMgSi₂O₆易成片长大的缺点,有效减少了陶瓷中残留的气孔,提高烧结体致密性.(Ca_0.7Mg_0.3)SiO₃在1320℃烧结后介电常数为6.62,品质因数为36962GHz.更多还原

【Abstract】 Using Ca（NO₃）₂·4H₂O, Mg（NO₃）2·6H₂O and Si（OC₂H₅）₄ as precursors, (Ca_1-xMg_x)SiO₃ powders were prepared by sol-gel method with varying x （0.1, 0.2, 0.3, 0.4, 0.5）. The phase constitution, sintering characteristic and dielectric properties of (Ca_1-xMg_x)SiO₃ ceramics were studied. The results showed that the solubility limitation of Mg²⁺ in CaSiO₃ was below 0.2 and CaSiO₃ phase was transformed into CaMgSi₂O₆ phase with substituting Ca²⁺ by Mg²⁺. When x was 0.3, the growth of grains was restrained and pores were decreased due to the coexistence of CaSiO₃ and CaMgSi₂O₆, and then the ceramic density was enhanced. The dielectric constant and quality factor of (Ca_0.7Mg_0.3)SiO₃ ceramic sintered at 1320 ℃ were 6.62 and 36962 GHz, respectively.更多还原