A Preisach characterization of the Barkhausen spectrum of a canonical ferromagnet SrRuO3

The irreversible response of a ferromagnetic pervoskite SrRuO3 with a Curie temperature TC=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 ∣ha∣⩽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 TC. 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.