Sintering behavior and microwave dielectric properties of BaTi_4O_9 ceramics prepared from different size powders by sol-gel method

摘要

The BaTi_4O_9 submicron powders were synthesized by a sol-gel method, and the sintering behavior and microwave dielectric properties of BaTi_4O_9 ceramics prepared from powders with different particle sizes were also investigated. The particle size of powders calcined at 700°C, 800°C, 900°C and 1000°C were 8-10 nm, 70-90 nm, 100-120 nm and 140-170 nm, respectively. The 70-170 nm powders benefited the sintering process and microwave dielectric properties, whereas nanoparticles with the size of 8-10 nm damaged the sintering behavior due to the more amorphous phases and lower green density introduced by the large surface area. Sintered at 1175°C, the BaTi_4O_9 ceramic prepared from 100-120 nm size nanoparticles had compact structure and exhibited good microwave dielectric properties of ε_r = 36.91 and Q×f = 29, 833 GHz.