Characterisation of Sm-Co-Sn alloys

Cast SmCo5-xSnx (x = 0.00, 0.01, 0.06 and 0.12) alloys were prepared by arc melting with subsequent thermal homogenisation. Microstructural and x-ray diffraction studies revealed that the alloys were constituted of three phases i.e. SmCo5, Sm2Co7 and Sm2Co17. The addition of Sn caused grain refinement of the alloys. It was found that the Sn addition promoted nucleation of Sm2Co17, segregation of solute atoms and increase in unit cell volume; consequently, significant augmentation in remanence to maximum magnetization ratios was achieved. - Research Highlights: 1. Tin up to 0.12% was added in a Samarium cobalt-SmCo5 system; discernable changes in the microstructure and phase distribution were achieved; → the nucleation of Sm2Co17 phase, → segregation of Sn and samarium rich Sm2Co7 phase on the grain boundaries → refinement of the microstructure in term of grain size 2. Moreover, addition of Sn caused twofold increase in magnetic properties (Remanence-Mr) of the Sm-Co alloy as compared to the binary SmCo5 system.