Magnetocaloric regenerators comprising materials containing cobalt, manganese and boron

A method for preparing a material, the method comprising:

• (a) providing a mixture of precursors comprising atoms of the elements cobalt, manganese, boron, and carbon,
• and
• (b) reacting the mixture provided in step (a) to obtain a solid reaction product, comprising—
• (b-1) reacting the mixture provided in step (a) in the solid phase obtaining a solid reaction product,
• and/or
• (b-2) transferring the mixture provided in step (a) or the solid reaction product obtained in step (b-1) into the liquid phase and reacting it in the liquid phase obtaining a liquid reaction product, and transferring the liquid reaction product into the solid phase obtaining a solid reaction product,
• and
• (c) optionally shaping of the solid reaction product obtained in step (b) to obtain a shaped solid reaction product,
• and
• (d) heat treatment of the solid reaction product obtained in step (b-1) or (b-2) or of the shaped solid reaction product obtained in step (c) to obtain a heat treated product,
• and
• (e) cooling the heat treated product obtained in step (d) to obtain a cooled product,
• and
• (f) optionally shaping of the cooled product obtained in step (e).