Structural and mechanical properties of RT_2Zn_(20) and RFe_(2-x)Co_xZn_(20)(R=Y, Sm; T=Fe, Ru, Os, Co, Rh and Ir)

摘要

The phase stability, crystal structure and mechanical properties of YT_2Zn_(20) and SmT_2Zn_(20) (T=Fe, Ru, Os, Co, Rh and Ir) compounds have been investigated by using interatomic potentials based on the lattice inversion technique. The calculated lattice constants are in good agreement with the experimental data. The lattice constants increase and Bulk modulus decrease as the transition metal T varies from 3d to 5d. The Y-based compounds with lower energies are more stable than the Sm analogs. Also, the Bulk modulus of YT_2Zn_(20) series are larger than SmT_2Zn_(20) series. Moreover, the mechanical properties of the quaternary compounds YFe_(2-x)Co_xZn_(20) and SmFe_(2-x)Co_xZn_(20), such as the elastic constants and bulk modulus, have been calculated in this work The substitution of Co atoms would decrease the cohesive energies and increase the bulk modulus of materials.