The role of Cu element in Fe 9.4 Co 6.7 Ni 6.6 Mn 0.9 V 0.9 Cu 2.4 magnetic high-entropy alloys

Spark plasma sintering (SPS) technology has obvious advantages in the preparation of high entropy alloys (HEAs) with high mechanical properties, but the mechanism of their magnetic enhancement is not clear. In this work, HEAs with high saturation magnetization (Ms) and excellent mechanical properties were designed and prepared. The properties of Fe 9.4 Co 6.7 Ni 6.6 Mn 0.9 V 0.9 HEA were optimized by adding Cu element, and the main phase of the HEAs was (face-centered cubic) FCC phase. The addition of Cu element mitigates the distortion of the FCC phase, resulting in an increase in the intensity of Ms value for the alloy from 118 emu/g to 143.7 emu/g. However, this also leads to a slight reduction in yield strength while still maintaining a high level at 1132 MPa. Theoretical calculations based on first principles indicate that the magnetic enhancement of these alloys is facilitated by an increase in the atomic magnetic moments of their ferromagnetic constituents.