Low-temperature magnetic properties and large magnetocaloric effects in the RE3Rh2 (RE = Nd, Ho and Er) intermetallics

The cryogenic magnetic properties and magnetocaloric effects of Er3Ni2-type Nd3Rh2 (space group R-3, N148, hR45), and Y3Rh2-type RE3Rh2 (RE = Ho, Er) (space group I4/mcm, N140, tI140) have been investigated in detail. For the Nd3Rh2 compound, two second-order magnetic transitions, a ferromagnetic-antiferromagnetic transition followed by an antiferromagnetic-paramagnetic transition with temperature increasing, are observed at Tt = 13 K and TN = 17 K, respectively. For the RE3Rh2 (RE = Ho, Er) compounds, it exhibits a ferromagnetic ordering around the Curie temperature 23 K and 8 K, respectively. The reciprocal magnetic susceptibility of RE3Rh2 (RE = Ho, Er) obey the Curie-Weiss law in the paramagnetic region, the values of the effective magnetic moment are determined to be 10.30 μB/Ho3+ and 10.62 μB/Er3+, and the corresponding paramagnetic Curie temperatures are 13 K and 4.5 K, respectively. The maximum values of magnetic entropy changes for RE3Rh2 (RE = Nd, Ho and Er) are achieved to be 3.78 J/kg K, 14.01 J/kg K and 20.01 J/kg K with an effect refrigerant capacity values of 68 J/kg, 382 J/kg and 267 J/kg for a field change of 0–5 T, respectively. Large magnetocaloric effects indicate the potentiality of the RE3Rh2 (RE = Nd, Ho and Er) compounds as candidates in low temperature magnetic refrigerant. •The intermetallic compounds RE3Rh2 with RE= Nd, Ho and Er have been synthesised.•Both the phenomenological universal curve and Landau theory were employed to determine the magnetic transition nature.•Large magnetocaloric effects in the RE3Rh2 compounds are observed at low temperature.