Nonasymptotic critical behaviour of uniaxial systems with strong dipolar interaction

Abstract

Within a field-theoretic renormalization group approach general relations between specific heat, susceptibility and order parameter for uniaxial dipolar ferromagnets or ferroelectrics are derived. An advantage of these relations is that no explicit solution of the flow equation for the temperature dependence of the effective four-point coupling is needed. In this way the crossover from critical behaviour to mean field behaviour can be studied. The theory is applied to LiTbF 4 and TSCC.