纳米CaMgSi_2O_6粉体的低温合成与微波介电性能

Synthesis and Microwave Dielectric Properties of CaMgSi_2O_6 Nanopowder Prepared at Low Temperature

以硝酸锂、偏钒酸铵、硝酸钙、硝酸镁、正硅酸乙酯为原料,采用溶胶-凝胶法低温合成纳米CaMgSi2O6微波介质陶瓷粉体,研究了不同粒径粉体的烧结行为与微波介电性能。结果表明,通过在钙镁硅溶胶中引入锂钒烧结助剂可大大降低陶瓷粉体的晶相合成温度,干凝胶在750℃煅烧后可获得主晶相为CaMgSi2O6、分散性良好、粒径为78￣98 nm的陶瓷粉体,可满足微型片式元器件用超薄陶瓷介质层的制备要求;该粉体在890℃烧结后获得致密结构的陶瓷,具有良好的微波介电性能:介电常数为7.68,品质因数为24542 GHz,频率温度系数为-57.25×10-6℃-1。

Using LiNO3, NH4O3, Ca（NO3）2·4H2O, Mg（NO3）2·6H2O and Si （OC2H5）4 as raw materials, CaMgSi2O6 microwave dielectric ceramic nanopowders were prepared at low temperature by sol-gel method. The sintering characteristic and dielectric properties of powders were studied. The results show that the crystallization temperature is decreased enormously by introduction of Li-V liquid phase sintering aids into Ca-Mg-Si materials, and the powder calcined at 750℃ has particle sizes of 78-98 nm with the CaMgSi2O6 as the main crystalline phase. The dielectric ceramic made from powders calcined at 750℃ achieves more compact structure at the sintering temperature of 890℃, and then has good microwave dielectric properties; the dielectric constant, quality factor and temperature prepare low temperature cofired minisize muhilayer component.