A Preisach characterization of the Barkhausen spectrum of a canonical ferromagnet SrRuO 3

Abstract

The irreversible response of a ferromagnetic pervoskite SrRuO 3 with a Curie temperature T C=160 K has been characterized experimentally by measuring the temperature dependence of the field cooled and zero field cooled moments over the temperature interval 5 K⩽ T ⩽180 K , in a sequence of applied fields up to the coercive field, and also the major hysteresis loop over the field range ∣ h a∣⩽40 kOe at a sequence of temperatures which span the ordered phase. The data have been analysed within the framework of a generalized version of the Preisach model of hysteresis which combines thermal fluctuations with the growth of the free energy barriers below T C. The numerical simulations replicate all of the principal structural systematics of the data, and yield details of the spectrum of Barkhausen instabilities in this material.