Atomistic simulation for disordered TbCu7-type compounds SmCo7 and Sm(Co,T)7 (T=Ti, Ga, Si, Cu, Hf, Zr)

The computational evolution from ordered SmCo 5 (CaCu 5 -type) compound to disordered SmCo 7 (TbCu 7 -type) compound has been implemented in this work. Based on statistical simulation, both the phase stabilities and the lattice constants of the calculated SmCo 7 series are in good agreement with experiments and a sort of 3g layer twisting deformation is observed. The calculated site preferences and lattice constants of the disordered ternary SmCo 7− x T x (T = Ti, Ga, Si, Cu, Hf, Zr) are also in consonance with experimental data. SmCo 7 's natural structure selection has also been investigated and understood on the basis of phase stability and cohesive energy. This work lays a foundation for further first principles studies on the magnetic properties of disordered TbCu 7 -type high-temperature permanent magnets.