Structural and dielectric properties of Ba3V2O8 ceramics

Polycrystalline sample of Ba3V2O8 was prepared by a high-temperature solid-state reaction technique. Preliminary X-ray diffraction (XRD) analysis confirms the formation of single-phase compound of hexagonal (rhombohedral) crystal structure at room temperature. Microstructural analysis by scanning electron microscope (SEM) shows that the compound has well defined grains, which are distributed uniformly throughout the surface of the sample. The dielectric properties of the compound studied in a wide frequency range (10(2)-10(6) Hz) at different temperatures (25-400 degrees C), exhibits that they are temperature dependent. Detailed analysis of impedance spectra showed that the electric properties of the material are strongly dependent on frequency and temperature. The activation energy, calculated from the temperature dependence of ac conductivity (dielectric data), was found to be 0.23 eV at 50 kHz in the higher temperature region. (C) 2008 Elsevier B.V. All rights reserved.