MURPHYS-HSFS-2014 - 7th International Workshop on Multi-Rate Processes & Hysteresis, 2nd International Workshop on Hysteresis and Slow-Fast Systems, April 7-11, 2014 - Abstract
Ktena, Aphrodite
Magnetic Barkhausen Noise (mBN) is the result of discrete magnetization jumps during the magnetization process of a material. The occurrence and size of the jumps is a stochastic, nonlinear phenomenon. mBN is therefore known to be related to magnetic hysteresis and effective magnetization reversal mechanisms. mBN data can be used as a measure of the energy necessary to nucleate or annihilate magnetic domains and overcome obstacles, such as crystal defects, grain misorientation & boundaries, impurities or dislocations, during magnetic domain wall propagation. The link between mBN data and a materials composition, phases, anisotropy, impurities, strain, dislocation density and grain size is being sought by several laboratories. The challenge is to decode the mBN signature of a material, decouple the effect of the microstructural features and map them to mBN phenomenology. In that direction, several modeling approaches at the microscopic, mesoscopic and macroscopic level have been proposed. Their main features and results are being presented and discussed with reference to the limitations imposed by the experimental procedure used to collect mBN data. Understanding and quantifying mBN is key to study in a macroscopic way the microstructure of magnetic materials and develop relevant, standardized industrial procedures, as in the non-destructive evaluation of magnetic materials.