Structural, magnetic and magnetocaloric properties of (Mn, Co)2(Si, P) compounds

• Mn1.2Co0.8Si0.2P0.8 shows an antiferro–ferromagnetic transition at 235 K.
• Addition of B leads to an increase of the transition temperature TN.
• A modest inverse magnetocaloric effect is observed at TN.

We report on various approaches to control the antiferro–ferromagnetic transition temperature of Mn1.2Co0.8Si0.2P0.8 and related materials for magnetocaloric applications. The effects of the Si substitution, Mn/Co ratio and B addition/substitution on MnCoP have been characterized by X-ray diffraction and magnetic measurements. In each case, these parameters have a great influence on the structural and magnetic properties. Silicon and boron turn out to be the elements suitable to substitute the phosphorous and bring TN closer to room temperature. The study thus paves the way for future tuning of the working temperature and adjustment of the magnetic properties. With entropy change of about 1.4 J kg−1 K−1 for 5 T, the inverse magnetocaloric effect of Mn1.2Co0.8Si0.2P0.8 is modest, but might present some interest for applications other than magnetic cooling.