Cold-preserving particle, group of cold-preserving particles, regenerator, refrigeration machine, cryogenic pump, superconducting magnet, device for nuclear magnetic resonance imaging, device for nuclear magnetic resonance, device for growing a single crystal by the pulling method using a magnetic field, and device for helium recondensation

Claims

1. A cold-preserving particle containing: nickel (Ni); at least one first element selected from the group consisting of yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu); at least one second element selected from the group consisting of silicon (Si) and germanium (Ge); crystalline phase of the SmNiGe3 type; and crystalline phase of the CeNiSi2 type and / or crystalline phase of the CaF2 type.

2. A cold-preserving particle according to claim 1, characterized in that in the case where the intensity of the peak corresponding to the (131) plane of the crystalline phase of the SmNiGe3 type, obtained by X-ray powder diffractometry, is determined as the intensity of the first peak (Ia), the intensity of the peak corresponding to the (131) plane of the crystalline phase of the CeNiSi2 type, obtained by X-ray powder diffractometry, is defined as the intensity of the second peak (Ib), and the intensity of the peak corresponding to the (111) plane of the CaF2 type crystalline phase obtained by X-ray powder diffractometry is defined as the intensity of the third peak (Ic), the ratio ((Ib + Ic) / Ia) of the sum of the intensities of the second and third peaks to the intensity of the first peak is equal to or greater than 0.01 and equal to or less than 0.

3.

3. A cold-preserving particle containing: nickel (Ni); at least one first element selected from the group consisting of yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu); at least one second element selected from the group consisting of silicon (Si) and germanium (Ge); crystalline phase of the SmNiGe3 type; and a first phase in which the atomic concentration of said at least one second element is higher than 70 at.%.

4. A cold-preserving particle according to claim 3, characterized in that the percentage share of the area of ​​the first phase in the cross-section is equal to or greater than 0.01% and equal to or less than 45%.

5. A cold-preserving particle according to claim 1 or 3, characterized in that if the perimeter of the projection image is designated L, and the actual area of ​​the projection image is designated A, the circularity R, represented by the expression 4πA / L 2 , more than 0.

5.

6. A cold-preserving particle according to claim 1 or 3, characterized in that the particle size is equal to or greater than 50 µm and equal to or less than 3 mm.

7. A cold-preserving particle according to claim 1 or 3, characterized in that the maximum value of the volumetric specific heat capacity in the temperature range of 25 K or below is equal to or greater than 0.38 J / (cm 3 ⋅K).

8. A group of cold-preserving particles containing a cold-preserving particle according to claim 1 or 3 in an amount equal to or greater than 90%.

9. A regenerator filled with a plurality of cold-retaining particles according to paragraph 1 or 3.

10. A refrigeration machine containing a regenerator according to paragraph 9.

11. A cryogenic pump containing a refrigeration machine according to claim 10.

12. A superconducting magnet containing a refrigeration machine according to claim 10.

13. A device for nuclear magnetic resonance imaging, comprising a refrigeration machine according to claim 10.

14. A nuclear magnetic resonance device comprising a refrigeration machine according to claim 10.

15. A device for growing a single crystal by pulling using a magnetic field, comprising a refrigeration machine according to claim 10.

16. A helium recondensation device comprising a refrigeration machine according to claim 10.