The Effect of Thermally Induced Relaxation on the Remanent Magnetization in a Moving Preisach Model

Abstract

The scalar Preisach model [1] is a mathematical representation of macroscopic hysteresis phenomena as a superposition of a continuum of “elementary” rectangular hysteresis cycles. The model incorporates the essential physical ingredients of anisotropy and interactions, both local and mean field, and can be generalized to include finite temperature relaxation effects. In recent years, the model has experienced a considerable revival of interest, particularly with regard to its potential to clarify the interpretation of Henkel plots [2,3], which are a valuable source of information on interparticle interaction effects. If the magnetizing remanence i_m(h_a) of a system of single-domain particles is measured by applying and then removing positive fields h_a starting from a demagnetized state, until the remanence is saturated at i_∞, and then the demagnetizing remanence i_d(-h_a) is measured by applying and removing negative fields -h_a starting from the saturated remanence state i_∞, until negative saturation -i_∞ is reached, then, according to Wohlfarth [4], these remanences satisfy the linear relationship i_d(-h_a) = i_∞ - 2i_m(h_a) if there are no interparticle interactions.