Structural variation and microwave dielectric properties of ZrO2 added Ba(Zn1/3Ta2/3)O-3 ceramics

Abstract

Ba(Zn1/3Ta2/3)O-3 (BZT) ceramic has 1 : 2 ordered hexagonal structure, but was destroyed with the addition of ZrO2. The 1 : 1 ordered cubic structure was developed when a large amount of ZrO2 was added. BZT has a porous and inhomogeneous microstructure with a Ba5Ta4O15 second phase. When ZrO2 was added, a new Ba0.5TaO3 second phase formed and grain growth occurred. Presence of liquid phase which is related to the Ba0.5TaO3 second phase could be responsible for the grain growth. Q value of BZT was greatly enhanced with the addition of ZrO2. The improvement of Q value can be explained by the increase of relative density and grain size. Especially, grain size is considered to be one of the crucial factors for the improvement of Q value of BZT ceramic.