Structural, magnetic and magnetocaloric properties of Ni 54 Mn 14 Ga 27 Fe 5 :The impact of annealing time

Abstract

The structural, magnetic and magnetocaloric properties of Ni54Mn14Ga27Fe5 Heusler alloy as a function of the annealing time have been investigated. The crystal structures have been characterized through multiphase Rietveld refinement of X-ray diffraction data. The alloys have cubic and the tetragonal structure with a mixed crystal phase at room temperature. In the magnetic measurements, the alloys exhibit the inter-martensitic and ferromagnetic-paramagnetic transition. The saturation magnetization values of the alloys decrease from 46.38 to 44.21 A m(2)kg(-1) as the annealing time is increased. The maximum magnetic entropy change is found to be as 2.8 Jkg(-1) K-1 under 2 T magnetic field.