Novel Co75Al8.4Si8.3Ti8.3 medium entropy alloy for both high magnetization and Curie temperature

A novel Co75Al8.4Si8.3Ti8.3 medium entropy alloy (MEA) with excellent magnetic properties was fabricated by vacuum induction melting (VIM). Micro-analysis confirms that the Co75Al8.4Si8.3Ti8.3 MEA is composed of FCC, BCC, and B2 phases, and atomic force microscope (AFM) reveals that the FCC and B2 phases have a distinct magnetic domain structure. The Co75Al8.4Si8.3Ti8.3 MEA exhibits a high saturation magnetization (Ms) of up to 132.13 emu/g at 10 K and maintains a high Ms of 105.4 emu/g at room temperature (298 K). This MEA remains ferromagnetic at 900 K indicating a Curie point (Tc) above this temperature. Compared to most existing high-entropy alloys, this alloy shows relatively high Ms as well as a high Tc.