MAGNETIC REFRIGERATION MATERIAL AND MAGNETIC REFRIGERATION DEVICE

Abstract

A magnetic refrigeration material has magnetic material particles with a magnetocaloric effect and an oxidation-resistant film formed on the surfaces of the magnetic material particles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically showing an outline sectional structure of a main portion of a magnetic refrigeration device according to an embodiment of the invention.

FIG. 2 is a diagram showing an outline sectional structure of the whole of the magnetic refrigeration device according to the embodiment of the invention.

FIG. 3 is a magnified diagram showing an outline sectional structure of a magnetic refrigeration material according to the embodiment of the invention.

FIG. 4 is a graph showing a relationship between a temperature span and a AMR heat cycle frequency.

Claims

1. A magnetic refrigeration material, comprising: magnetic material particles having a magnetocaloric effect; andan oxidation-resistant film formed on the surfaces of the magnetic material particles.

2. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film is formed of a nonmagnetic material.

3. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film is formed after removing the surface layer which is formed on the surfaces of the magnetic material particles.

4. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film has a heat conductivity of 9 W/m·K or more.

5. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film is at least one kind of element selected from aluminum oxide and aluminum nitride.

6. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film is copper, and the surface of the oxidation-resistant film is coated with a discoloration preventing agent.

7. The magnetic refrigeration material according to claim 1, wherein the oxidation-resistant film has an average film thickness of 1 to 50 μm.

8. The magnetic refrigeration material according to claim 1, wherein the magnetic material particles are formed of an LaFe13 magnetic material.

9. A magnetic refrigeration device, comprising: a magnetic refrigeration material having magnetic material particles with a magnetocaloric effect and an oxidation-resistant film formed on the surfaces of the magnetic material particles;a housing section for housing the magnetic refrigeration material;a magnet for applying a magnetic field to the magnetic refrigeration material within the housing section; anda heat transfer fluid delivery mechanism for flowing a heat transfer fluid in the housing section.

10. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film is made of a nonmagnetic material.

11. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film is formed after removing the surface layer which is formed on the surfaces of the magnetic material particles.

12. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film has a heat conductivity of 9 W/m·K or more.

13. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film is at least one kind of element selected from aluminum oxide and aluminum nitride.

14. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film is copper, and the surface of the oxidation-resistant film is coated with a discoloration preventing agent.

15. The magnetic refrigeration device according to claim 9, wherein the oxidation-resistant film has an average film thickness of 1 to 50 μm.

16. The magnetic refrigeration device according to claim 9, wherein the magnetic material particles are formed of an LaFe13 magnetic material.