Cold storage material, refrigerator, device incorporating superconducting coil, and method of manufacturing cold storage material

A magnetic cold storage material for a cold storage refrigerator, comprising:

• a granular body including an intermetallic compound, wherein the granular body has a ThCr2Si2 structure occupying 80% by volume or more in the granular body, and has a crystallite size in a range of 70 nm or less,
• wherein the granular body has a particle size range of 0.01 mm to 1 mm,
• a shape coefficient of the granular body, represented by M/A, is in a range of 1.0 to 5.0 in every projection direction, wherein an area of a projected image of the cold storage material is defined as A and an area of a smallest circumscribed circle circumscribing the projected image is defined as M,
• the Th site in the ThCr2Si2 structure is at least one element selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Tm, Yb, Lu, Sc, and Y,
• the Cr site in the ThCr2Si2 structure is at least one element selected from the group consisting of Ti, V, Fe, Ni, and Cu, and
• the Si site in the ThCr2Si2 structure is at least one element selected from Si or Ge.