Large magnetocaloric effect in triangular antiferromagnet ErPd2Sb

Adiabatic demagnetization refrigeration (ADR) has been considered as an main method for achieving temperature below 1 K. Due to the absence of long-range magnetic ordering at extremely low temperature, frustrated magnets are very competitive in cryogenic magnetic refrigerants. In this paper, we investigated the magnetocaloric effect of triangular antiferromagnet ErPd2Sb. No evident manetic ordering can be observed at temperature above 0.56 K. Large volumetric magnetic entropy change of 172.8 mJ·cm−3·K−1 is obtained under a small field change of 2 T at 1.3 K, which is larger than that of commercial magnetic refrigerant Gd3Ga5O12 under the same condition. Due to the strong magnetic frustration, the minmum temperature of ErPd2Sb is revealed to be 254.8 mK by quasi-ADR measurement, which is much lower than its magnetic ordering temperature. In addition, a field-induced phase trantition can be marked in ADR curve at 0.5 T, which is consistent with the measurement results of electrical resistivity. These excellent magnetocaloric effects indicate that ErPd2Sb is an ideal candidate for ultra-low temperature magnetic refrigeration application.