Magnetic refrigerants for the 4.2-20 K region: garnets or perovskites?

Abstract

Rare earth orthoaluminates (REOA) REAlO3, the compounds with perovskite structure, are compared with garnets with a view to finding an effective working material for 4.2-20 K magnetic refrigerators. It appears from the meanfield calculations that orthoaluminates are more advantageous than Gd3Ga5O12, Dy3Ga5O12 and Dy3Al5O12, the garnets which so far have been considered the most promising refrigerants.