Microstructure evolution and phase analysis of Sm60Ni40 alloy

•Phase formation in Sm60Ni40 experimentally verified with equilibrium phase diagram.•Sm3Ni2 phase has been resolved to be of monoclinic crystal structure.•Anisotropic nature of Sm3Ni2 phase exhibits high coercivity with Tc of 110 K. The paper investigates the microstructure evolution and phase analysis of the Sm60Ni40 alloy. The arc melted sample retained the high temperature stable (>873 K) Sm7Ni3 and Sm3Ni2 phases along with the congruently melting SmNi phase. Annealing the as-cast sample at 903 K for 100 h stabilized the high temperature stable (873 K − 903 K) Sm3Ni2 phase. Rietveld refinement was performed to resolve the crystal structure of Sm3Ni2 phase and it was observed that Sm3Ni2 phase stabilizes in monoclinic crystal structure (space group: C2/m) with a lattice parameter of a = 13.49 Å, b = 3.75 Å, c = 9.68 Å and β = 106.6°. The Curie temperature of the Sm3Ni2 phase was determined to be ∼ 110 K. The high squareness ratio of 82 % along with high coercivity of 3 T indicates that the Sm3Ni2 phase possess spontaneous uniaxial magnetic anisotropy.