Finite temperature properties of rare earth free Fe4CoSi permanent magnet

• Published in: Current applied physics 2024, 63(0), , pp.66-71
• Main Authors: Siraj Ul, Haq, Khan, Imran, Hong, Jisang
• Format: Article
• Language: English
• Subjects: Energy product; Fe4CoSi alloy; Permanent magnet; Rare-earth-free; VAMPIRE; 물리학
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2024.03.010

Developing rare-earth free permanent magnet is attracting extensive research efforts for several device applications and other issues. Here, we investigate the temperature-dependent magnetic properties of the Fe4CoSi alloy. The Fe4CoSi alloy shows a high critical temperature of 980 K with perpendicular magnetic anisotropy. At room temperature, it exhibits a magnetization of 1.44 T, anisotropy constant of 0.8 MJ/m3, and a magnetic hardness parameter of 0.75. We obtain the (BH)max of 554 kJ/m3 at 0 K, 410 kJ/m3 at 300 K, and 215 kJ/m3 at 600 K without demagnetization effect. Even with a demagnetization factor of 0.3, the Fe4CoSi alloy still possesses the (BH)max of 268 kJ/m3 at room temperature. The Fe4CoSi exhibits better permanent magnetic properties compared with ferrites and SmCo5. This may imply that the Fe4CoSi alloy can be a potential Fe-based gap permanent magnet between ferrite and Nd-Fe-B (or Sm–Co) at room temperature. [Display omitted] •Finite temperature-dependent properties of bulk Fe4CoSi have been investigated.•The Fe4CoSi system has a ferromagnetic ground state with a high Curie temperature of 980 K.•The Fe4CoSi possesses sufficient HC and (BH)max of 0.9 T and 410 kJ/m3 comparable to NdFeB (445 kJ/m3) at 300 K.•Fe4CoSi has (BH)max of 268 kJ/m3 at 300 K higher than standard ferrites (50 kJ/m3) even with a demagnetization factor of 0.3.•Overall, the Fe4CoSi is designed theoretically as a promising candidate for rare earth-free permanent magnets.