Eur. Phys. J. B 40, 145-151 (2004)
https://doi.org/10.1140/epjb/e2004-00253-3

Interpreting remanence isotherms: a Preisach-based study

Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2, Canada

Corresponding author: ^a roshko@cc.umanitoba.ca

Received: 15 January 2004
Revised: 16 April 2004
Published online: 12 August 2004

Abstract

Numerical simulations of the field dependence of the isothermal remanent moment (IRM) and the thermoremanent moment (TRM) are presented, based on a Preisach formalism which decomposes the free energy landscape into an ensemble of thermally activated, temperature dependent, double well subsystems, each characterized by a dissipation field H_d and a bias field H_s. The simulations show that the TRM approaches saturation much more rapidly than the corresponding IRM and that, as a consequence, the characteristics of the IRM are determined primarily by the distribution of dissipation fields, as defined by the mean field and the dispersion , while the characteristics of the TRM are determined primarily by a mixture of the mean dissipation field and the dispersion of bias fields . The simulations also identify a regime , where the influence of on the TRM is negligible, and hence where the TRM and the IRM provide essentially independent scans of the Preisach distribution along the two orthogonal H_s and H_d directions, respectively. The systematics established by the model simulations are exploited to analyze TRM and IRM data from a mixed ferromagnetic perovskite Ca_0.4Sr_0.6RuO₃, and to reconstruct the distribution of characteristic fields H_d and H_s, and its variation with temperature.