Difficulties Caused by Magnetic After-effect during Identification of the Preisach Hysteresis Model Weighting Function

Abstract

The time dependence of the magnetic hysteresis caused by thermal activation over an energy barrier is called after-effect, magnetic viscosity, or magnetic relaxation. Magnetic after-effect influences the hysteresis loop shape depending on an excitation filed rate of change, the sample geometry, and the state. The magnetizing loop changes, especially at rounding of peaks at steep part of the loop, severely influences process of the Preisach model weighting function identification from experimental data. This article deals with the after-effect measuring with the aim of determining limiting excitation speed.