Magnetic properties of new glassy Fe–Au(Cu)–B alloys

Abstract The evolution of the microstructure and soft magnetic properties of Fe 76 Au 4− x Cu x B 20 and Fe 87 Au 2− x Cu x B 11 melt spun ribbons prepared at different cooling rates were investigated. The samples are stable above room temperature and display saturation induction up to 1.79 T and magnetic permeabilities of over 2×10 4 at 300 K. The structure is not fully amorphous, as proved by DSC and HRTEM investigations, but consists of very small grains of about 10 nm, randomly dispersed in the amorphous residual matrix. The grains composition strongly depends on the B content.