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Phase relations and microwave dielectric properties of vanadium modified Ba5Nb4O15 ceramics

2006; Elsevier BV; Volume: 61; Issue: 16 Linguagem: Inglês

10.1016/j.matlet.2006.11.095

1873-4979

Fei Zhao, Hao Zhuang, Zhenxing Yue, Jing Pei, Zhilun Gui, Longtu Li,

Dielectric properties of ceramics

Abstract Microwave dielectric ceramics of Ba5Nb4−xVxO15 (x = 0–1) were prepared by a solid-state reaction method. Vanadium substitution can markedly lower the sintering temperature of Ba5Nb4O15 from 1450 to 1100 °C. The X-ray powder diffraction analysis reveals the multiphase nature of this system. A hexagonal-to-orthorhombic phase transition was also observed for the BaNb2O6 secondary phase. The microwave dielectric properties, such as τf, er and Q × f value, decreased with increasing vanadium content for samples sintered at 1100 °C. There was an apparent increase in τf and Q × f value for samples (x ≥ 0.5) sintered at 1200 °C due to the hexagonal-to-orthorhombic phase transition of the BaNb2O6 phase. These results suggested that the microwave dielectric properties of multiphase ceramics strongly depended on the phase compositions and the phase transitions.