Composition and property optimization of rare-earth-free Mn-Al-C magnet by phase stability and magnetic behavior analysis

Mn-Al-C system offers a possibility of rare-earth-free permanent magnets with the reduced temperature-dependent deterioration magnetic properties. The alloy composition and properties have been optimized via calculations electronic structures phase stability L10-ordered ferromagnetic τ-phase (Mn0.5Al0.5)100−xCx. WIEN2k program package, Vienna Ab-initio simulation package (VASP), Alloy Theoretic Automated Toolkit (ATAT) were used to calculate identify optimal carbon content for most stable L10-structured Mn-Al-C. We Brillouin function Callen-Callen semiempirical relation obtain saturation magnetization magnetocrystalline anisotropy constant at elevated temperatures. It was found that 2.33 at% gives L10 (Mn0.5Al0.5)100−xCx has lowest formation energy highest among studied contents (x = 0–3.03 at%). 0 K increases increasing content. Therefore, carbon-doped Mn-Al becomes magnetically harder than pure Mn50Al50. However, decreases 300 as increases. Curie temperature 590 x from 685 0.0. estimated approximately 130 emu/g K, leading 18 MGOe under Bs Br Hci> Br/2. it is highly probable potentially fills gap between 10 30 magnets. results in this study quantify explain reason widely studying 2 systems.