Temperature Dependence of Polarizability in Sodium Potassium Tantalate Mixed Ceramic System

Abstract

Using a quadratic anharmonic model Hamiltonian and using double time temperature dependent Green’s function method and Dyson’s equation treatment, expression for polarizability in the frequency response for mixed perovskite type ferroelectrics have been obtained. Using the experimentally observed temperature dependent dielectic constant, loss tangent, soft mode frequency, width for Na1-xKxTaO3 (x=0,0.2,0.4,0.5 and 0.6) the polarizability has been calculated for these samples at 10kHz