studying the effects of nano sintering additives on microstructure and electrical properties of potassium-sodium niobate piezoceramics

In this paper, lead free (k0.48,na0.52)nbo3 (knn(48-52)) piezoelectric ceramics were made by the conventional solid-state sintering process. in order to decrease the sintering temperature and modify the dielectric, piezoelectric and ferroelectric properties, sintering additives of nano zno (n-zno), nano cuo (n-cuo) and nano sno2 (n-sno2) were used. phase structure and microstructure were analyzed by using x-ray diffractometry and scanning electron microscopy techniques, and the edx analysis was used to study the zno distribution at grains and grain boundaries. the highest piezoelectric constant of d33= 150 pc/n was obtained for knn(48-52) with 0.6 mol% n-zno at a sintering temperature of 1070°c, which is two times larger than the pure knn(4852) at the sintering temperature of 1112 °c. additionally, the knn(48-52) ceramics co-doped with 0.8 mol% nzno, 0.5 mol% n-cuo and 0.8 mol% n-sno2, showed dielectric and piezoelectric properties of d33= 97 pc/n, tanδ = 0.006 and εr = 172 at the sintering temperature of 960 °c, which were much better than corresponding values for pure knn at 1110°c.