Classical Diagram Technique for Calculating Thermostatic Properties of Solids; Application to Dielectric Susceptibility of Paraelectrics

Abstract

A diagram technique suitable for calculating equilibrium classical statistical properties of solid dielectrics is developed. The method is applied to the temperature-dependent dielectric susceptibility and vibration spectrum of an anharmonic crystal. The techniques of "diagram summation" and "frequency renormalization" are used to obtain a Curie-law formula for the susceptibility of paraelectric materials. The method is extended to obtain a new formula for the susceptibility in the presence of a biasing field. Some possible applications of the theory to relevant experiments are mentioned.