Role of V on the coercivity of SmFe₁₂-based melt-spun ribbons revealed by machine learning and microstructure characterizations

We employed machine-learning of a dataset extracted from literature on Sm(Fe,X)₁₂-based alloys to understand the most influential parameters for coercivity. V-addition is found to be most influential to coercivity. The microstructure origin for coercivity in Sm_xFe₁₁Ti and Sm_xFe₁₀TiV (1.0≤x ≤ 2.1) melt-spun ribbons was investigated experimentally. Unlike V-free alloys, ThMn₁₂-type structure can be stabilized in a wide range of x =1.03-1.62 in Sm_xFe₁₀TiV ribbons. Coercivity increases from 0.51 T for Sm_0.99Fe₁₁Ti to 1.1 T for Sm_1.06Fe₁₀TiV optimally-annealed ribbons. The enhanced coercivity originates from formation of a Sm-enriched intergranular phase enveloping the SmFe₁₂-based grains, increasing pinning force against the magnetic domain-wall propagation.