溶胶-凝胶法制备Ba2Ti9O20陶瓷的烧结性能与微波介电性能(英文)

Sintering Behavior and Microwave Dielectric Properties of Ba_2Ti_9O_(20) Ceramics by Sol-Gel Method

采用溶胶-凝胶法制备了Ba2Ti9O20亚微米粉体,对不同煅烧温度获得粉体的物相、形貌以及粒径进行了表征,并对以不同粒径粉体为起始原料制备Ba2Ti9O20陶瓷的烧结性能与微波介电性能进行了研究。结果表明,干凝胶经过700,800,900,1000℃煅烧后,分别获得了粒子直径在l020,5080,80-150,150--180 nm的粉体。粒径在50180 nm的粉体利用细小颗粒的高比表能有效促进了Ba2Ti9O20陶瓷的烧结,而粒径在1020 nm的粉体则因粉体在成形过程中因高比表面积带来的较低体积密度,以及在烧结过程中无定型态向晶态的转变,恶化了陶瓷的烧结性能。900℃煅烧获得的粒径在80150 nm的粉体烧结性能最好,在1150℃烧结后可以获得致密结构的陶瓷,并具有优良的微波介电性能:εr=38.22,Q×f=19,621 GHz。

The Ba_2Ti_9O_(20) powders were synthesized by a sol-gel method,and the sintering behavior and microwave dielectric properties of Ba_2Ti_9O_(20) ceramics prepared from powders with different particle sizes were also investigated.The particle size of powders calcined at 700,800,900 and 1000 ℃ were 10~20,50~80,80~150 and 150~180 nm,respectively.The 50~180 nm powders benefited the sintering process and microwave dielectric properties,whereas nanoparticles with the size of 10~20 nm damaged the sintering behavior due to the more amorphous phases and lower green density introduced by the large surface area.Sintered at 1150℃,the Ba_2Ti_9O_(20) ceramic prepared from 80~150 nm size nanoparticles had compact structure and exhibited good microwave dielectric properties of ε_r =38.22 and Q×f= 19,621 GHz.