Induced Magnetic Anisotropy and Thickness Dependence of Magnetic Properties in Nanocrystalline Alloy "Finemet"

The magnetic field-induced magnetic anisotropy and thickness dependence of magnetic properties in the nanocrystalline alloy "Finemet" were investigated. Compared with amorphous alloys, it was difficult to induce a magnetic anisotropy in Finemet at low temperatures. However, magnetic anisotropy in Finemet could be easily induced by annealing at temperatures above 700 K, and the anisotropy increased with increasing annealing temperature and time. The magnetic properties of Finemet at high frequencies were improved by decreasing the thickness. This thickness dependence was similar to that for Co-based amorphous alloys. Thin Finemet materials are especially suited for use in magnetic components for use at high frequencies, because of their low core losses and high permeability at high frequencies.