Thermodynamic modeling of the Co-Sm system

The Phase diagram of Sm-Co system was assessed by applying calculation of phase diagram (CALPHAD) technique. Thermochemical and equilibrium information in literatures were critically evaluated, and a series of self-consistent thermodynamic parameters capable of formulating the Gibbs free energies of every phase were obtained. There are eight compounds in this system. Based on the analysis of experimental data and phases\u2019 crystal structures, SmCo5 was modeled as (Co, Va)0.833333(Co2, Sm)0.166667 and Sm2Co17 as (Co)0.833333(Sm)0.111111(Co2, Sm)0.055556. Other six intermetallic phases, Sm3Co, Sm9Co4, SmCo2, SmCo3, Sm2Co7, and Sm5Co19, were treated as stoichiometric compounds. Calculation based on these parameters can reproduce most of the experimental data well