Temperature dependence of semi-hard iron silicide rare-earth free magnet

Abstract

Searching for rare-earth free permanent magnet attracts extensive research interests due to diverse technological applications and other subtle issues. Here, the temperature dependent magnetic properties of Fe5SiC structure are explored. The Fe5SiC has a critical temperature of 710 K with perpendicular magnetic anisotropy. The magnetic anisotropy constant and coercive field are monotonically decreased with increasing temperature. For instance, the magnetic anisotropy constant is 0.42 MJ m−3 at zero Kelvin and reduced to 0.24 MJ m−3 and 0.06 MJ m−3 at 300 K and 600 K. The coercive field becomes 0.7 T at 0 K. With increasing the temperatures, it is suppressed to 0.42 T and 0.20 T at 300 K and 600 K, respectively. Overall, the Fe5SiC system has a (BH)max of 417 kJ m−3 at zero Kelvin. The (BH)max is decreased at high temperature. Nonetheless, we obtain the (BH)max of 234 kJ m−3 at 300 K. Since the Fe5SiC shows better permanent magnetic (PM) property than the conventional ferrites and also CeCo5. This finding may indicate that the Fe5SiC can be a potential candidate as a Fe-based gap PM between ferrite and Nd–Fe–B (or Sm–Co) at room temperature.