Magnetoresistance and magnetocaloric effect in metamagnetic alloys Ni45Co5Mn36.5In13.5

Magnetoresistance (MR) and magnetocaloric effect around martensitic transformation were investigated in a Ni45Co5Mn36.5In13.5 alloy. The martensitic temperature (T-M) locates at similar to 260 K. An external magnetic field can drive T-M to a lower temperature at a rate of similar to 9.2 K/T. Associated with the field-induced metamagnetic behaviors, a large MR takes place. The maximal MR exceeds 80% under a field of 5 T around 235 K. More attractive is that the MR behavior is fully recoverable against magnetic field. We also studied the magnetocaloric effect associated with the martensitic transformation and found a large magnetic entropy change (Delta S) around 252 K. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3359806]