Large magnetocaloric effect at low magnetic field in Ni50-xCoxMn35In15 ribbons

Recently, the magnetocaloric effect (MCE) of Ni-Mn-based Heusler alloys has attracted more attention due to its metamagnetic shape-memory effect. However, most MCE investigations focused on the bulk alloys developed at high magnetic field (>2 T). In this paper, by employing the melt-spinning technique, a large MCE at low magnetic field was found in a ribbon of Ni50-xCoxMn35In15. The magnetic entropy change Delta S reaches the maximum value of 5.35 J/kg K at 1 T field in the Ni49CoMn35In15 ribbon near room temperature, and its corresponding temperature span arrives 24 K. The refrigerant capacity is enhanced with the increase of the Co substitution. Such a large MCE at low magnetic field in the Ni50-xCoxMn35In15 ribbon with a wide temperature range provides a potential candidate for room temperature magnetic refrigeration. (C) 2011 American Institute of Physics. [doi:10.1063/1.3540649]