Analysis of Distribution of the Surface Magnetic-Field Gradient in (PrDy)(FeCo)B Rare-Earth Magnets

Abstract

The main parameters of the domain structure of a (PrDy)(FeCo)B sintered permanent magnet are determined using magnetic force microscopy analysis of the magnetic-gradient distribution near the magnet surface. It is shown that the domain wall energy and width are not sensitive to the replacement of Nd with Pr and Dy in the studied RE-TM-B alloy. The anisotropy and exchange interaction constants are obtained. Two competitive processes of magnetization reversal (pinning and nucleation) are defined in sintered permanent magnets (PrDy)(FeCo)B.