CuTa_2O_6掺杂Ba(Zn_(1/3)Ta_(2/3))O_3基微波陶瓷烧结动力学及微波性能

结合烧结动力学模型和微观形貌观察,研究未掺杂和掺杂CuTa_2O_6的Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷在1 270~1 520℃温度范围内的致密化过程和烧结动力学机理。结果表明:在1 150℃以上烧结,随温度升高,Ba(Zn_(1/3)Ta_(2/3))O_3的烧结机制从体积扩散向晶界扩散转变。掺杂0.25%CuTa_2O_6可显著加快Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷的烧结致密化过程,在显著降低烧结温度的同时,可大幅缩短烧结时间并有效地促进B位的有序化。掺杂Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷在1370℃烧结12h即可获得96%的相对密度,在1 370℃烧结12 h后的介电常数(εr)和品质因数(Q·f)分别约为29.4和985 35;相比较,未掺杂Ba(Zn_(1/3)Ta_(2/3))O_3在1 520℃烧结12 h的εr和Q·f分别只有27.4和68 147。掺杂Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷经1 520℃烧结48 h的εr和Q·f分别约为28.2和103 131。

Sintering kinetics and microwave properties of CuTa2O6 doped Ba(Zn1/3Ta2/3)O3ceramics

Combined with classical sintering model and morphology evolution, the sintering kinetics of undoped and CuTa2O6 doped Ba(Zn1/3Ta2/3)O3 ceramics in a temperature range of 1270?1520℃ were studied using a nonisothermal method. The results show that, when the sintering temperature is over 1150℃, the sintering mechanism of Ba(Zn1/3Ta2/3)O3 changes from the bulk diffusion to the grain boundary diffusion. In addition to the enhancement of B-site ordering, 0.25% CuTa2O6 doping can significantly accelerate the densification process of Ba(Zn1/3Ta2/3)O3 ceramics and effectively reduce the sintering temperature and holding time. CuTa2O6 doped Ba(Zn1/3Ta2/3)O3ceramics can obtain more than 96% relative sintering density when being sintered at 1370℃ for 12 h. The dielectric constant (εr) and quality factor (Q·f) of 0.25% CuTa2O6 doped Ba(Zn1/3Ta2/3)O3 are about 29.4 and 98 535, respectively. In contrast,εr andQ·f of undoped Ba(Zn1/3Ta2/3)O3sintered at 1520℃ for 12 h are 27.4 and 68147, respectively. Furthermore, those of CuTa2O6 doped Ba(Zn1/3Ta2/3)O3 can increase to 28.2 and 103131 after being sintered at 1520℃ for 48 h, respectively.