Improved Stability and Magnetic Anisotropy in L10 -FeNi by Interstitial Doping : A First-Principles Prediction

Author / Creator

MMM 2020 (2020)

Conferences

MMM 2020 D4: Hard Magnetic Materials: Nanostructures and Others (2020)

Available as

Online

Summary

Due to remarkable success in many uses today such as motors in an electric vehicle and memory devices, there have been intensive research interests centered at synthesizing a rare earth (RE)-free p...

Due to remarkable success in many uses today such as motors in an electric vehicle and memory devices, there have been intensive research interests centered at synthesizing a rare earth (RE)-free permanent magnetic material that has a cheap cost for mass production and various methods to improve a uniaxial magnetic anisotropy (Ku), saturation magnetization (µ0Ms) as well as thermal stability of the previously known materials. RE-free L10 ordered FeNi alloys boast with affordable cost, large µ0Ms and also notable Ku owing to their tetragonal structure but has very low stability and degree of ordering. Herein, through first-principles electronic structure calculations, we have studied possible improvements of the structural stability and magnetic properties of L10-FeNi by an interstitial doping with 2p-electron elements (B, C, and N). It is found that the additions of 12.5 at.% B and N enhance Ku up to 0.9 and 1.8 MJ/m3, respectively, which are 35% and about 3 times larger than that (0.66 MJ/m3) of FeNi. More importantly, unlike the C and N dopants, the B greatly improves the stability and reaches Ku of 2.8 MJ/m3 at 25 at.%. These results demonstrate the feasibility of possible enhancements on the magnetic anisotropy and energy product of 3d-only metals for RE-free permanent magnet applications.

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