1. Magnetocrystalline anisotropy of interstitially and substitutionally Sn-doped MnBi for high temperature permanent magnet applications.
- Author
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Choi, Minyeong, Hong, Yang-Ki, Won, Hoyun, Yeo, Chang-Dong, Choi, Byung-Chul, Park, Jihoon, and Lee, Woncheol
- Subjects
MAGNETIC anisotropy ,HIGH temperatures ,MAGNETIC moments ,CURIE temperature ,PERMANENT magnets ,MAGNETIZATION ,IRON clusters - Abstract
First-principles calculations were performed to calculate the electronic structures of low temperature phase (LTP) MnBi (Mn
50 Bi50 ) and substitutionally and interstitially Sn-doped MnBi [Mn50 Bi25 Sn25 , (Mn0.5 Bi0.5 )66.7 Sn33.3 ]. Brillouin function predicts the temperature dependence of saturation magnetization M(T). Sn substitution for Bi in MnBi (Mn50 Bi25 Sn25 ) changes the magnetocrystalline anisotropy constant (Ku ) from −0.202 MJ/m3 (the in-plane magnetization) for LTP MnBi to 1.711 MJ/m3 (the out-of-plane magnetization). In comparison, the Ku remains negative but slightly decreases to −0.043 MJ/m3 when Sn is interstitially doped in MnBi [(Mn0.5 Bi0.5 )66.7 Sn33.3 ]. The Curie temperature (TC ) decreases from 716 K for LTP Mn50 Bi50 to 445 K for Mn50 Bi25 Sn25 and 285 K for (Mn0.5 Bi0.5 )66.7 Sn33.3 . Mn50 Bi25 Sn25 has a lower magnetic moment of 5.034 μB /f.u. but a higher saturation magnetization of 64.2 emu/g than (Mn0.5 Bi0.5 )66.7 Sn33.3 with a magnetic moment of 6.609 μB /f.u. and a saturation magnetization of 48.2 emu/g because the weight and volume of the substitutionally Sn-doped MnBi are smaller than the interstitially Sn-doped MnBi. The low Curie temperature and magnetization for Sn-doped MnBi are attributed to the high concentration of Sn. Thus, future study needs to focus on low Sn-concentrated MnBi. [ABSTRACT FROM AUTHOR]- Published
- 2023
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