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 sint ering aids were prepared and investigated for microstructure and micro wave 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 co efficient. Dielectric losses increase significantly at additive levels higher than 0.15 wt%. The combined additives La2O3 and ZnO act as gra in growth enhancers. With 0.15 wt% additives, a ceramic having a diele ctric constant, a quality factor, and a temperature coefficient of fre quency at 4.2 GHz of 37.6, 12800, and -2.9 ppm/degrees C, respectively , was obtained. The quality factor was considerably improved by prolon ged sintering.