3D interconnected nanoporous FeCo soft magnetic materials synthesized by liquid metal dealloying

Abstract

FeCo alloys are important soft magnetic materials with the highest saturation magnetizations, high Curie temperature, high permeability, and low losses. In this study, 3D interconnected nanoporous (3DNP) FeCo soft magnetic materials were produced by liquid metal dealloying (LMD). Ni atoms were selectively dissolved from (FeCo)xNi100−x precursor alloys into Mg metallic melt, and Fe and Co atoms self-organized 3DNP structures. Morphology and grain boundary characteristics depended on the LMD processing temperature and Ni concentration in precursor alloy. Developed 3DNP FeCo materials demonstrated soft magnetic properties with high saturation magnetization over 220 emu/g. Although 3DNP structure increases hysteresis loss due to its porosity, it leads to lower eddy current loss than bulk FeCo at high frequencies. The LMD process has advantages for synthesizing nanostructured FeCo with high magnetization and low coercivity.