Exchange interaction in rapidly solidified nanocrystalline RE–(Fe/Co)–B hard magnetic alloys

Abstract

The exchange interactions for rapidly solidified (Nd/Pr)(Fe/Co)B hard magnetic alloys with remanence enhancement were studied by analyzing characteristic magnetic curves and Henkel plots. The exchange coupling can be improved by increasing soft phase content within hard matrix. With increasing temperature, the exchange interaction is enhanced due to the increased exchange length. An increased recoil susceptibility was found for the alloys with improved exchange coupling. Analysis of the microstructure parameters indicated that Co substituting Fe and introducing soft α-(Fe,Co) phase not only reduce the stray field effects but also enhance the exchange interaction.