The effect of grain boundary microstructure on Barkhausen noise in ferromagnetic materials

The Barkhausen noise (BHN) was measured in ferromagnetic materials to investigate the interaction between the grain boundary microstructure and magnetic domain walls. The grain-size effect of the BHN was studied for pure iron specimens. The Hall-Petch type relationship between the grain-size and the BHN power was found. The effect of the grain-boundary misorientation on the BHN was also studied for silicon steel specimens. The BHN power increased with increasing the grain boundary misorientation angle. It has been suggested that the arrangement of magnetic domains along a grain boundary can be affected by the grain boundary character and that hysteresis of magnetization can be optimized by controlling the grain boundary microstructure in ferromagnetic materials. The importance of understanding the behavior of magnetic domains was discussed in terms of the control of magnetic properties in ferromagnetic materials.