STATIC CROSSOVER IN UNIAXIAL DIPOLAR FERROMAGNETS

A field theoretic description of the static crossover in uniaxial dipolar ferremagnets is presented. On the basis of a generalized minimal subtraction scheme we analyze the crossover from Ising behavior with non-classical exponents to asymptotic uniaxial dipolar behavior, which is characterized by classical exponents with logarithmic corrections. By comparing our theoretical results with specific heat and susceptibility measurements on LiTbF4 we find quantitative agreement, where solely the strength of the dipolar coupling constant enters as an adjustable parameter.