Enhanced room temperature magneto-caloric effect in Ni-Mn-In films with Fe/Co substitution

The influence of small amounts of replacement of Mn with Co/Fe on the structural, magnetic, and magneto-caloric properties of polycrystalline off-stoichiometric Ni-Mn-In Heusler alloy films has been investigated. An enhancement in Curie temperature (T-C) up to 317 K was observed upon Fe substitution. The change in magnetic entropy (Delta S-M) and refrigeration capacity (RC) across the second order ferromagnetic to paramagnetic phase transition increased significantly upon substituting Fe/Co in Mn sites. Delta S-M (RC) estimated for a magnetic field change of 18 kOe near T-C increased from -7.93 x 10(4) erg/cc K (1.98 x 10(6) erg/cc) to -12.79 x 10(4) erg/cc K (2.82 x 10(6) erg/cc) and -9.99 x 10(4) erg/cc K (2.60 x 10(6) erg/cc) in similar to 3 at.% Fe and Co substituted Ni-Mn-In films, respectively. Published under license by AIP Publishing.