Effects of La2O3/ZnO additives on microstructure and microwave dielectric properties of Zr0.8Sn0.2TiO4 ceramics

Dielectric ceramics of Zr0.8Sn0.2TiO4 containing La2O3 and ZnO as sintering aids were prepared and investigating for microstructure and microwave dielectric properties. Low-level doping with La2O3 and ZnO (up to 0.30 wt%) is good for densification and dielectric properties. These additives do not affect the dielectric constant and the temperature coefficient. Dielectric losses increase significantly at additive levels higher than 0.15 wt%. The combined additives La2O3 and ZnO act as grain growth enhancers. With 0.15 wt% additives, a ceramic having a dielectric constant, a quality factor, and a temperature coefficient of frequency at 4.2 GHz of 37.6, 12,800 and -2.9 ppm/C, respectively, was obtained. The quality factor was considerably improved by prolonged sintering