Electrical transport properties and giant baroresistance effect at martensitic transformation of Ni43.7Fe5.3Mn35.4In15.6 Heusler alloy

The electrical transport properties at martensitic transformation (MT) in polycrystalline Ni43.7Fe5.3Mn35.4In15.6 have been intensively investigated under different hydrostatic pressures. For this alloy, the experimental results show that applying a higher hydrostatic pressure can convert its MT from the metamagnetic type into the paramagnetic type. It provides a unique opportunity to separate the relative contributions of electron-spin and electron-lattice scatterings across the metamagnetic MT based on the dynamical Clausius-Clapeyron equation, which delivers a deeper insight into the resistivity change of metamagnetic MT for the Mn-rich Ni-Mn based Heusler alloys. In addition, the studied alloy also reveals a giant positive baroresistance (BR) effect with a saturated value of 115% at 242 K. This performance originates from the combined effect of electron-spin and electron-lattice scatterings associated with a prominent hydrostatic pressure-induced MT, which contribute 46% and 69% to the overall BR ratio, respectively.