Magnetic material for magnetic refrigeration
Magnetic materials, having: a composition represented by a general formula: (R 1−y X y ) x (Fe 1−a M a ) 100−x where, R is at least one of element selected from the group consisting of La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, X is at least one of element selected from the group consisting of Ti, Zr and Hf, M is at least one of element selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Nb, Mo, Ta, W, Al, Si, Ga and Ge, x is a value satisfying 4≦x≦20 atomic %, y is a value satisfying 0.01≦y≦0.9, and a is a value satisfying 0≦a≦0.2, wherein the magnetic material includes a Th 2 Ni 17 crystal phase or a TbCu 7 crystal phase as a main phase, that are useful for magnetic refrigeration.
1. A magnetic refrigeration device, comprising:
a heat regenerator; and
a magnetic material filled in the heat regenerator, comprising:
a composition represented by a general formula:
(R 1−y X y ) x Fe 100−x
wherein R is at least one element selected from the group consisting of La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y,
X is at least one element selected from the group consisting of Ti, Zr and Hf,
x is a value satisfying 4≦x≦20 atomic %,
y is a value, which is atomic ratio, satisfying 0.01≦y≦0.9, and
a crystalline structure having a Th 2 Ni 17 crystal phase or a TbCu 7 crystal phase as a main phase,
wherein a refrigeration cycle of the magnetic refrigeration device is performed by using a magnetic entropy change associated with a second order magnetic phase transition of the magnetic material.
2. The magnetic refrigeration device according to claim 1 , wherein the magnetic material has a Curie temperature of 320K or less.
3. The magnetic refrigeration device according to claim 1 , wherein the magnetic material has a Curie temperature of from 250K to 320K or less.
4. The magnetic refrigeration device according to claim 2 , wherein 50 atomic % or more of the element R is at least one element selected from the group consisting of Ce, Pr, Nd and Sm.
5. The magnetic refrigeration device according to claim 1 , wherein the element R is at least one element selected from the group consisting of Ce, Pr, Nd and Sm.
6. The magnetic refrigeration device according to claim 1 , wherein x is a value satisfying 8≦x≦15 atomic %.
7. The magnetic refrigeration device according to claim 1 , wherein y is a value, which is atomic ratio, satisfying 0.01≦y≦0.5.
8. The magnetic refrigeration device according to claim 1 , wherein the magnetic material has the magnetic entropy change of from 2.2to 2.8J/kg·K.
9. A magnetic refrigeration device, comprising:
a heat regenerator; and
a magnetic material filled in the heat regenerator, comprising:
a composition represented by a general formula:
(R 1−y X y ) x (Fe 1−z M z ) 100−x
wherein R is at least one element selected from the group consisting of La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y,
X is at least one element selected from the group consisting of Ti, Zr and Hf,
M is at least one element selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, Ta, W, Al, Si, Ga and Ge,
x is a value satisfying 4≦x≦20 atomic %,
y is a value, which is atomic ratio, satisfying 0.01≦y≦0.9,
z is a value, which is atomic ratio, satisfying 0<z<0.2, and
a crystalline structure having a Th 2 Ni 17 crystal phase or a TbCu 7 crystal phase as a main phase,
wherein a refrigeration cycle of the magnetic refrigeration device is performed by using a magnetic entropy change associated with a second order magnetic phase transition of the magnetic material.
10. The magnetic refrigeration device according to claim 9 , wherein the magnetic material has a Curie temperature of 320K or less.
11. The magnetic refrigeration device according to claim 9 , wherein the magnetic material has a Curie temperature of from 250K to 320K or less.
12. The magnetic refrigeration device according to claim 9 , wherein 50 atomic % or more of the element R is at least one element selected from the group consisting of Ce, Pr, Nd and Sm.
13. The magnetic refrigeration device according to claim 9 , wherein the element R is at least one element selected from the group consisting of Ce, Pr, Nd and Sm.
14. The magnetic refrigeration device according to claim 9 , wherein x is a value satisfying 8≦x≦15 atomic %.
15. The magnetic refrigeration device according to claim 9 , wherein y is a value, which is atomic ratio, satisfying 0.01≦y≦0.5.
16. The magnetic refrigeration device according to claim 9 , wherein the element M is at least one element selected from the group consisting of V, Cr, Mn, Co, Ni, Nb, Mo, Al, Si and Ga.
17. The magnetic refrigeration device according to claim 10 , wherein the magnetic material has the magnetic entropy change of from 2.2to 2.8 J/kg·K.