Calorimetric and magnetic study for Ni${}_{50}$Mn${}_{36}$In${}_{14}$ and relative cooling power in paramagnetic inverse magnetocaloric systems

Abstract

The non-stoichiometric Heusler alloy Ni${}_{50}$Mn${}_{36}$In${}_{14}$ undergoes a martensitic phase transformation in the vicinity of 345 K, with the high temperature austenite phase exhibiting paramagnetic rather than ferromagnetic behavior, as shown in similar alloys with lower-temperature transformations. Suitably prepared samples are shown to exhibit a sharp transformation, a relatively small thermal hysteresis, and a large field-induced entropy change. We analyzed the magnetocaloric behavior both through magnetization and direct field-dependent calorimetry measurements. For measurements passing through the first-order transformation, an improved method for heat-pulse relaxation calorimetry was designed. The results provide a firm basis for the analytic evaluation of field-induced entropy changes in related materials. An analysis of the relative cooling power (RCP), based on the integrated field-induced entropy change and magnetizing behavior of the Mn spin system with ferromagnetic correlations, shows that a significant RCP may be obtained in these materials by tuning the magnetic and structural transformation temperatures through minor compositional changes or local order changes.

References in corpus (3)

• Inverse magnetocaloric effect in ferromagnetic Ni-Mn-Sn alloys
• Magnetic superelasticity and inverse magnetocaloric effect in Ni-Mn-In
• Entropy change at the martensitic transformation in ferromagnetic shape memory alloys Ni_{2+x}Mn_{1-x}Ga

Cited by in corpus (7)

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• Relative Cooling Power Enhancement by Tuning Magneto-structural Stability in Ni-Mn-In Heusler Alloys
• Thermo-magnetic characterization of phase transitions in a Ni-Mn-In metamagnetic shape memory alloy
• Large anomalous Nernst effect across the magneto-structural transition in bulk Ni-Co-Mn-Sn full Heusler alloy
• Measurement independent magnetocaloric effect in Mn-rich Mn-Fe-Ni-Sn(Sb/In) Heusler alloys
• Effect of site occupancy disorder on Martensitic properties of Mn${}_2$NiIn type alloys: x-ray absorption fine structure study
• Experimental method to determine specific heat and transition enthalpy at a first order phase transition: fundamentals and application to a NiMnIn Heusler alloy