Microstructure and Microwave Dielectric Properties of SnO₂-Added Ba(Zn_1/3Ta_2/3)O₃ Ceramics

Abstract

The Ba(Zn 1/3 Ta 2/3 )O 3 (BZT) ceramic normally has a 1:2-ordered hexagonal structure, but it changes to the 1:1-ordered cubic structure with the addition of SnO 2 . When SnO 2 was added to the BZT ceramics, grain growth occurred and the liquid phase formed. The liquid phase was responsible for the grain growth. The Q × f value of the BZT ceramic significantly increased with the addition of a small amount of SnO 2 . Since the degree of 1:2 ordering and the relative density decreased with the addition of SnO 2 , the enhancement of the Q value cannot be explained by the 1:2 ordering and the relative density. On the other hand, the improvement of the Q value could be related to the increase in the grain size because the average grain size increased with the addition of SnO 2 . However, when a large amount of SnO 2 was added, the Q value was very low. The low Q value was explained by the low relative density and the presence of a large amount of Ba 3 Ta 5 O 15 phase.