MAGNETIZATION PROCESS IN NANOCRYSTALLINE FERROMAGNETS

Annealing of initially amorphous FeCuNbSiB alloys at temperatures above their crystallization temperature leads to an ultrafine grain structure of alpha-FeSi with average grain sizes down to D almost-equal-to 10 nm and random texture. Owing to the nanocrystalline structure the magneto-crystalline anisotropy is randomly averaged out by exchange interaction. Moreover magnetostriction decreases on crystallization owing to the formation of alpha-FeSi. As a consequence the material reveals excellent soft magnetic properties.