Mixed magnetism (the coexistence of strong and weak magnetism in one material) is regarded as the origin of the giant magnetocaloric effect (GMCE). A good example is ${(\mathrm{Mn},\mathrm{Fe})}_2(\mathrm{Si},\mathrm{P})$, which is established as one of the best magnetocaloric materials available. Tuning the material properties are essential for optimizing its performance, and a straightforward way to do that is by doping. In this article, an ab initio electronic structure method was used to calculate the structure and magnetic properties of $3d$-transition-metal-doped ${(\mathrm{Mn},\mathrm{Fe})}_2(\mathrm{Si},\mathrm{P})$ materials for magnetocaloric applications (transition metals are Cr, Co, Mn, Ni, Cu). For a steady performance, the material should be mechanically stable. A detailed analysis of the elastic constants shows that the mechanical stability of the ${(\mathrm{Mn},\mathrm{Fe})}_2(\mathrm{Si},\mathrm{P})$ system increases significantly by doping with boron without affecting the magnetic properties. Insights of the influence of doping enable future studies to understand and predict better magnetocaloric materials.

• Received 9 November 2015
• Revised 18 January 2016

DOI:https://doi.org/10.1103/PhysRevB.93.094110