Dielectric, Resistive and Conduction Characteristics of Lead-Free Complex Perovskite Electro-Ceramic: (Bi1/2K1/2)(Zn1/2W1/2)O3

Abstract

We have investigated the electric field and temperature dependence of dielectric, impedance and conduction characteristics of a lead-free complex distorted perovskite (Bi1/2K1/2)(Zn1/2W1/2)O3 ceramic. The material was synthesized by using a standard high-temperature ceramic technology. Analysis of x-ray diffraction data and patterns collected at room temperature has provided the information on the formation of a distorted perovskite with an orthorhombic crystal system. Dielectric and impedance spectroscopy techniques have been utilized to study the effect of frequency and temperature on the dielectric, impedance and transport (conduction) characteristics of the compound. The mechanism of dielectric relaxation phenomenon in the compound has been analyzed using the dielectric and impedance data collected in a wide range of temperature (100–500°C) and frequency (1 kHz–1 MHz). Analysis of temperature-frequency-dependent Nyquist (impedance) plots has shown an important role of grains (bulk) and grain boundaries in the capacitive and resistive characteristics of the material. Based on the frequency-dependent electrical modulus and impedance data of the compound, the dielectric relaxation of non-Debye type has been suggested. The nature of the temperature- and frequency-dependence of ac conductivity of the compound follows Joncher’s power law. The fabricated compound has some important dielectric characteristics which can potentially be used for electronic devices.