Dynamic magnetic response near TC

Abstract
Linear response theory is applied to the frequency dependence of the ac magnetic susceptibility of iron whiskers and nickel platelets in the region of the Curie temperature. It is shown that a particular form of a magnetic memory function can be used in formulations based on either or both magnetic viscosity and/or relaxation toward equilibrium. This memory function corresponds to a relaxation rate that follows a power law in time as proposed by Ngai and White.