Effect of Magnetic Field on Performance of ErNi0.9Co0.1 Regenerator in Gifford-McMahon Refrigerator

Specific heat of magnetic material ErNi0.9Co0.1 was measured in a temperature interval between 1.5 and 35 K in magnetic fields up to 5 T. This material exhibited a large specific heat suitable for a cryogenic regenerator. The Curie temperature was 6.2 K, which is lower than that of ErNi, 10.5 K. The Gifford‐McMahon cycle with an ErNi0.9Co0.1 regenerator was numerically simulated and the results were compared to those for ErNi. The cooling power obtained with ErNi0.9Co0.1 was 1.4 times higher than with ErNi in a zero magnetic field. When a constant magnetic field of 1.0 T was applied to the ErNi0.9Co0.1 regenerator, the cooling power was 1.2 times larger than in a zero magnetic field.