Influence of Ge Doping on the Magnetic Properties and Microstructure of Fe-Si-B-P-Cu Alloys Prepared with Industrial Raw Materials

Abstract

With the increasing demand for energy efficiency and miniaturization, there is a growing need for magnetic materials with high saturation magnetic flux density (Bs) and low coercivity (Hc). Here, Fe82.3Si4B9P4-xCu0.7Gex (x=0, 1, 2) nanocrystalline ribbons were prepared using industrial raw materials (IRMs). We found that appropriate Ge doping can optimize Bs by enhancing the crystallization volume fraction of α-Fe phase, and refine grain size by increasing the energy barriers for the growth of α-Fe and Fe(B, P) phases, which ultimately reduces Hc. However, Ge over-doping can also induce surface crystallization of the ribbons due to the enrichment of Cu elements. Excessive diffusion of Cu into the crystalline layer is not favorable for grain refinement, which deteriorates the soft magnetic properties of the ribbons.

Keywords: Nanocrystalline alloy, Ge, Industrial raw materials, Surface crystallization, Magnetic properties.