Barkhausen noise emission in Fe-resin soft magnetic composites

Abstract

This paper investigates the potential of Barkhausen noise emission for characterisation of soft magnetic composites based on ferromagnetic powders and resin coating. The powder samples are investigated as a function of variable resin fraction, as well as particle size, by the use of Barkhausen noise and EBSD techniques. Magnetic domain wall's thickness and energy are calculated and the first constant of magneto-crystalline anisotropy is determined from magnetisation curves measured via a vibrating magnetometer. Moreover, the domain walls alignment is analysed and correlated with the Barkhausen noise signals and the extracted parameters. It was found that a reduced resin fraction, as well as increasing particle size of the ferromagnetic particles, contributes to the stronger Barkhausen noise emission. In this particular case, the Barkhausen noise emission strongly correlates with the coercive field whereas the correlation with hysteresis loss is weaker.