Zn_(0.99)Cu_(0.01)Al_2O_4-TiO_2基微波介质陶瓷的研究

Research on Zn_(0.99)Cu_(0.01)Al_2O_4-TiO_2 Microwave Dielectric Ceramics

以分析纯ZnO、CuO、Al2O3以及TiO2为原料,采用传统固相法制备了(1-x)Zn0.99Cu0.01Al2O4-x TiO2(ZCAT,x=0-0.25)微波介质陶瓷。研究了不同TiO2的添加量对ZCAT陶瓷烧结性能、晶相组成、显微结构以及微波介电性能的影响。研究结果表明:Zn0.99Cu0.01Al2O4与TiO2以两相的形式共存,不会形成固溶体;烧结温度随着TiO2添加量的增大显著降低;ZCAT陶瓷的体积密度、品质因数随着TiO2含量的增多而减小,介电常数则随着TiO2含量的增多而增大,添加适量TiO2将ZCAT陶瓷的频率温度系数调节至近零。当x=0.23时,陶瓷可在1380℃烧结3 h后获得最佳的微波介电性能:介电常数εr=11.4,品质因数Q×f=38155 GHz以及谐振频率温度系数τf=-2.4×10-6/℃。

（1-x） Zn0. 99Cu0. 01Al2O4-x TiO2（ ZCAT,x = 0-0. 25） ceramics were prepared via the conventional solid-state route using ZnO,Cu O,Al2O3,TiO2 as raw materials. The effects of TiO2 additives on sintering properties,phase composition,microstructure and microwave dielectric properties were investigated. The results show that Zn0. 99Cu0. 01Al2O4 and TiO2 can coexist with each other and form a two-phase system. The sintering temperature significant decreases by increasing TiO2 content. The bulk volume density and the quality factor of ZCAT decreases,while the dielectric constant of ZCAT increases as the TiO2 content increasing. The frequency temperature coefficient could adjust nearly-zero by adding an appropriate amount of TiO2. The optimal microwave dielectric properties were obtained in 0. 77Zn0. 99Cu0. 01Al2O4-0. 23 TiO2with the dielectric constant εr= 11. 4,the quality factor Q × f = 38155 GHz and the frequency temperature coefficient τf=- 2. 4 × 10-6/ ℃ which was sintered at 1380 ℃ for 3 h in air.