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

Abstract

Searching for rare-earth free permanent attracts extensive research interests due to diverse technological applications and other subtle issues. Here, we explore the temperature dependent magnetic properties of Fe5SiC structure. We obtain that 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, we obtain the magnetic anisotropy constant of 0.42 MJ/m3 at zero Kelvin, and it is suppressed to 0.24 MJ/m3 and 0.06 MJ/m3 at 300 K and 600 K. Similarly, we find the coercive field of 0.7 T at 0 K, and it becomes 0.42 T and 0.20 T at 300 K and 600 K. Overall, we find that the Fe5SiC system has a (BH)max of 39 MGOe at zero Kelvin. The (BH)max is decreased at high temperature. Nonetheless, we obtain the (BH)max of 24 MGOe at 300 K. Since the Fe5SiC shows better permanent magnetic property than the conventional ferrites and also CeCo5. Thus, we propose that the Fe5SiC can be a potential candidate as a Fe-based gap permanent magnet between ferrite and Nd-Fe-B (or Sm-Co) at room temperature.