Enhancing intrinsic magnetic properties and phase stability in SmFe11Ti through elemental substitution: A first-principles approach

Abstract

ThMn₁₂-type SmFe₁₁Ti has been identified as a structurally stable phase in its bulk form; however, the presence of Ti markedly suppresses its intrinsic magnetic performance. Herein, we employ density functional theory and Monte Carlo simulations to investigate partial substitution of Ti with simple metal and metalloid elements as a strategy to enhance intrinsic magnetic properties without compromising structural stability. Our results reveal that Al substitution is particularly effective, with SmFe₁₁Al_0.5Ti_0.5 achieving a saturation magnetization of 0.97 T and a magnetocrystalline anisotropy of 6.3 MJ/m³ at room temperature. These values lead to substantial improvements in the theoretical maximum energy product, anisotropic field, and hardness parameter, exceeding those of conventional SmFe₁₁Ti. The enhancements are attributed to modifications in the electronic energy levels of the strongly spin–orbit coupled Sm $4f$ orbitals upon elemental substitution. These findings provide a promising pathway for developing high-performance permanent magnets with reduced rare-earth content, supporting sustainable advanced permanent magnetic materials.