Controlled variation of parameters of magnetocaloric materials

2:

• The kit according to claim 1,
• wherein each of the Z magnetocaloric materials comprises:
• (i) a phase having a hexagonal structure of composition M2X with a crystal lattice having space group P-62m in a weight fraction of from 80% to 100%,
• (ii) a phase having a cubic structure of composition M3X with a crystal lattice having space group Fm-3m in a weight fraction of from 0% to 20%, and
• (iii) a phase having a hexagonal structure of composition M5X3 with a crystal lattice having space group P63/mcm in a weight fraction of from 0% to 20%,
• wherein in each case,
• M denotes atoms of elements selected from the group consisting of Fe and Mn and
• X denotes atoms of elements selected from the group consisting of P, Si, C, N and B,
• wherein for each of the Z magnetocaloric materials, sum of weight fractions of phases (i), (ii) and (iii) is 100%, and
• wherein each of the Z magnetocaloric materials differs from each of the other Z-1 magnetocaloric materials by the weight fractions of at least two of the phases (i), (ii) and (iii).

5:

• A magnetocaloric regenerator comprising:
• Z magnetocaloric materials,
• wherein each of the Z magnetocaloric materials is a composition of formula (I):
• (MnxFe1−x)2+uPySivCzNrBw (I),
• wherein
• 0.3≤x≤0.7;
• −0.12≤u≤0.10;
• 0.3≤y≤0.75;
• 0.25≤v≤0.7;
• 0≤z≤0.15;
• 0≤r≤0.1;
• 0≤w≤0.1;
• (y+v+w)≤1.05;
• (y+v+w+r)≥0.95;
• wherein u, x, y, v, z, r and w are identical for each of the Z magnetocaloric materials,
• wherein Z≥2, and
• wherein a Curie temperature of each of the Z magnetocaloric materials differs from a Curie temperature of each of other Z-1 magnetocaloric materials by at least 0.5 K.

11:

• A process for preparing Z magnetocaloric materials, wherein Z≥2, the process comprising:
• (a) providing a mixture of precursors comprising atoms of elements iron, manganese, phosphorus, silicon and optionally one or more of elements carbon, nitrogen and boron;
• (b) reacting the mixture to obtain a solid reaction product;
• (c) optionally shaping of the solid reaction product to obtain a shaped solid reaction product;
• (d) optionally exposing the solid reaction product or the shaped solid reaction product to an atmosphere comprising one or more hydrocarbons to obtain a carburized product;
• (e) heat treatment of the solid reaction product or the shaped solid reaction product or the carburized product at a heat treatment temperature to obtain a heat treated product, wherein the heat treatment temperature in (e) in preparing each of the Z magnetocaloric materials is different from the heat treatment temperature in (e) in preparing each of other Z-1 magnetocaloric materials;
• (f) cooling the heat treated product to obtain a cooled product;
• and
• (g) optionally shaping of the cooled product,
• wherein each of the Z magnetocaloric materials is a composition of formula (I):
• (MnxFe1−x)2+uPySivCzNrBw (I),
• wherein
• 0.3≤x≤0.7;
• −0.12≤u≤0.10;
• 0.3≤y≤0.75;
• 0.25≤v≤0.7;
• 0≤z≤0.15;
• 0≤r≤0.1;
• 0≤w≤0.1;
• (y+v+w)≤1.05;
• (y+v+w+r)≥0.95;
• wherein u, x, y, v, z, r and w are identical for each of the Z magnetocaloric materials, and
• wherein a Curie temperature of each of the Z magnetocaloric materials differs from a Curie temperature of each of other Z-1 magnetocaloric materials by at least 0.5 K.

16:

• The process according to claim 11, wherein the reacting (b) comprises:
• (b-1) reacting the mixture in a solid phase to obtain the solid reaction product;
• and/or
• (b-2) transferring the mixture or the solid reaction product into a liquid phase and reacting it in the liquid phase to obtain a liquid reaction product, and transferring the liquid reaction product into a solid phase to obtain the solid reaction product.