High Curie temperature and high magnetization potential Fe2CoS alloy soft magnet

Developing soft magnets is attracting extensive research efforts for several device applications and other issues. Here, we investigate the finite temperature magnetic properties of the Fe2CoS alloy using first-principles density functional theory calculations and Monte Carlo simulations. Without a demagnetization factor, it exhibits semi-hard-magnetic properties at room temperature. For instance, it exhibits a coercivity of 290 mT, a magnetic anisotropy constant of 218 kJ/m3, and a magnetic hardness parameter of 0.3. By considering the demagnetization factor at 300 K, the coercivity, magnetic anisotropy constant, and hardness parameter are reduced to 1.5 mT, 0.7 kJ/m3, and 0.035. Besides, compared to ferrites soft magnets, the Fe2CoS alloy shows a high relative permeability of 10000 and low energy loss of 0.16 Watt/kg. The curie temperature (940 K) and high saturation magnetization MS (1.49 T) of the Fe2CoS alloy are significantly higher than those of soft ferrites and Permalloy. Therefore, we propose that the Fe2CoS alloy can be used as a potential Fe-based soft magnet.