Microwave dielectric properties of multi-ions Ba(Zn,Ta)O3-based perovskite ceramics

In this study, Ba(Zn1/3Ta2/3)O3-based complex perovskite compounds, including Ba(Zn1/3Ta2/3)O3, Ba(Zn1/3Ta1/3Nb1/3)O3, Ba(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3, and Ba1/2Sr1/2(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3, were prepared and characterized. There was no second phase formation shown in the XRD patterns. Though it has been suggested that substitutions of multiple ions over A-site or B-site of the Ba(Zn1/3Ta2/3)O3 ceramics may not be beneficial to their microwave dielectric properties, the Ba(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3 and Ba1/2Sr1/2(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3 ceramics in this study were found to perform in a fairly acceptable manner. The Ba(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3 ceramic (sintered at 1575 °C for 6 h) and the Ba1/2Sr1/2(Zn1/6Co1/6Ta2/9Nb2/9Sb2/9)O3 ceramic (sintered at 1550 °C for 6 h) reported the following characteristics after annealing at 1400 °C for 10 h: 24.9 and 27.0 for dielectric constants (ɛr), 83,000 and 32,100 GHz for quality factors (Q × f) values and −12.8 and −22.6 ppm/°C for temperature coefficients of resonance frequency (τf).