Effect of element doping on the structural stability, magnetic properties and electronic structure of SmCo5-based rare earth permanent magnets

•Preferential occupancy of different doping elements in SmCo5 crystal lattice was illustrated.•Structural stability and magnetic properties of the doped systems were investigated.•Mechanism of doping elements to increase structural stability and magnetic moment was revealed.•Concentration effect of doping elements on structural stability and magnetic properties was studied. Doping transition metals has been proven as an effective method to enhance the performance of Sm-Co based rare earth permanent magnets. However, due to the complex interactions involved, the specific effects on magnetic properties, atomic occupancy preferences and structural stability mechanisms are still to be further investigated. In this study, we systematically investigated the influence of various transition metal dopants on the structural stability, magnetic properties and electronic structure of SmCo5 rare earth permanent magnet using first-principles calculations. Our calculations show that Ti, V, Cr, Mn, Ni, Cu, Zn elements preferentially occupy the 3 g site, while Sc and Zr tend to occupy the 1a site, and Fe elements have a preference for the 2c site. Regarding structural stability, doping with Sc, Cr, Mn, Fe, Ni, Cu, Zn and Zr all contribute to enhancing structural stability, while Ti and V doping exhibit adverse effects. Magnetic calculations indicate that doping with Mn and Fe significantly increases the total magnetic moment of the SmCo5 system. Notably, at a high doping concentration of 60 at%, the Ni and Zn-doped systems exhibit an exceptionally large magnetocrystalline anisotropy energy Additionally, a change in the magnetic easy axis direction occurs when the doping concentrations of Cr, Fe, Cu and Zn reach 60 at%, 40 at%, 40 at% (and 60 at%), 40 at% (and 60 at%), respectively. Our work provides important theoretical guidance for further optimizing the performance of Sm-Co based rare earth permanent magnets.