Field induced sign reversal of magnetocaloric effect in Gd2In

We report the magnetocaloric effect in the metamagnetic compound Gd2In obtained from magnetization measurement. Gd2In was previously reported to have two magnetic transitions: (i) a paramagnetic to ferromagnetic transition below 190 K and (ii) a ferromagnetic to an antiferromagnetic state below 105 K. The low temperature antiferromagnetic state is unstable under an applied magnetic field and undergoes metamagnetic transition to a ferromagnetic like state. We observe conventional positive magnetocaloric effect (the magnetic entropy change, Delta S-M < 0) around 190 K at all applied fields. The magnetocaloric effect is found to be inverse (negative) at low fields around 105 K (Delta S-M > 0), however it turns positive at higher fields (Delta S-M < 0). The observed anomaly is found to be related to the field induced transition which drives the system from an antiferromagnetic to a ferromagnetic state. (C) 2011 Elsevier B.V. All rights reserved.