Magnetic properties and phase stability of tetragonal Ce1-xSmxFe9Co2Ti 1:12 phase for permanent magnets

Highlights: • Sm substitution for Ce improves the magnetic properties in Ce_1-xSm_xFe₉Co₂Ti alloys. • Ribbons have suitable properties for medium-grade permanent magnets applications. • For high Ce concentrations, Co atoms redistributes in the crystal structure. In this work, we report the effects of partial substitution of Ce by Sm in CeFe₉Co₂Ti alloys on their magnetic and structural properties. The alloys were prepared in bulk and melt-spun ribbons. The alloys present the ThMn₁₂ phase in the full range of substitutions, and reach anisotropy fields above 8 T for the best alloy. After heat treatment, melt-spun ribbons show high values of magnetization (>112 A m²/kg), Curie temperatures >370 °C and enhanced coercivity. Although the coercivity values obtained are already suitable for permanent magnet applications, they are still low as compared to the anisotropy field (less than 6%). Coercivity is expected to improve by optimizing the microstructure of the best samples.