EFFECT OF STRUCTURAL CHANGES ON THE MICROWAVE DIELECTRIC PROPERTIES OF Ba(Zn1/3Nb2/3)O3 CERAMICS

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 41, no. 5A, pp. 2978-2981. 2002 Part 1. Vol. 41, no. 5A, pp. 2978-2981. 2002, 2002, Vol.41 (5A), p.2978-2981
• Main Authors: Noh, S-Y, Yoo, M-J, Nahm, S, Choi, C-H, Park, H-M, Lee, H-J
• Format: Article
• Language: English
• ISSN: 0021-4922
• DOI: 10.1143/JJAP.41.2978

The microstructure and microwave dielectric properties of Ba(Zn1/3Nb2/3)O3 (BZN) ceramics have been investigated. BZN has a 1:2 ordered hexagonal structure, and the degree of 1:2 ordering decreased with increasing sintering temperature. Liquid phase was found for the BZN sintered at > 1350 C, the evaporation of ZnO was responsible for the formation of liquid phase. BaNb6O16 second phase was also found for the specimens sintered at > 1350 C and the liquid phase has a composition close to that of BaNb6O16 second phase. The Q-value of BZN was increased with increasing sintering temperature and BZN sintered at 1400 C for 6 h has the maximum Q-value. Since the 1:2 ordering decreased with the sintering temperature, the enhancement of Q-value is not related to 1:2 ordering. The increase of the average grain size could be responsible for the increase of the Q-value, and the relative density also influenced the Q-value. BZN ceramics were sintered for various times at 1400 and 1300 C and the variation of Q-value was explained in terms of grain size and relative density. 11 refs.