Impedance Characteristics of a New TungstenBronze Vanadate: NaPb_2V_5O_(15)

摘要

The new complex Pb based vanadate, NaPb2V5O(15)(NPV), of tungsten bronzestructure was synthesized by a solid state reaction technique realized at low temperature,(i.e.,550~0C). The X-ray diffraction analysis shows that the sample has orthorhombic structure atroom temperature. The SEM micrograph of NPV shows that the grains are homogeneouslydistributed throughout the sample. The dielectric and impedance properties of NPV, measured ina wide frequency (10~2-10~6Hz) and temperature (room temperature-500~0C) range show that thecompound exhibits phase transition at 210~0C (10kHz).The ac electrical conductivity (σ_(ac)) of thematerial was found to be temperature dependent.