Magnetic material for magnetic refrigeration

Abstract

A magnetic material for magnetic refrigeration has a composition represented by (R1 1-y R2 y ) x Fe 100-x (R1 is at least one of element selected from Sm and Er, R2 is at least one of element selected from Ce, Pr, Nd, Tb and Dy, and x and y are numerical values satisfying 4≦x≦20 atomic % and 0.05≦y≦0.95), and includes a Th 2 Zn 17 crystal phase, a Th 2 Ni 17 crystal phase, or a TbCu 7 crystal phase as a main phase.

1 . A magnetic material for magnetic refrigeration, comprising:
 a composition represented by a general formula:
   (R1 1-y X y ) x Fe 100-x    
   where, R is at least one of element selected from La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y,   X is at least one of element selected from Ti, Zr and Hf,   x is a value satisfying 4≦x≦20 atomic % and   y is a value satisfying 0.01≦y≦0.9,
 wherein the magnetic material comprises a Th 2 Ni 17  crystal phase or a TbCu 7  crystal phase as a main phase. 
   
   
   
       2 . The material according to  claim 1 ,
 wherein the magnetic material exhibits a second order magnetic phase transition.   
   
   
       3 . The material according to  claim 1 ,
 wherein the magnetic material has a Curie temperature of 320K or less.   
   
   
       4 . The material according to  claim 1 ,
 wherein the element R comprises 50 atomic % or more of at least one selected from Ce, Pr, Nd and Sm.   
   
   
       5 . The material according to  claim 1 ,
 wherein the element R comprises at least one selected from the group consisting of Ce, Pr, Nd and Sm.   
   
   
       6 . The material according to  claim 1 ,
 wherein the value y is in a range from 0.01 to 0.5.   
   
   
       7 . The material according to  claim 1 ,
 wherein a part of the Fe is replaced by at least one of element selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, Zn, Nb, Mo, Ta, W, Al, Si, Ga and Ge.   
   
   
       8 . The material according to  claim 1 ,
 wherein a part of the Fe is replaced by at least one of element selected from the group consisting of Ni, Co, Mn, Cr, V, Nb, Mo, Al, Si and Ga.