The influence of martensite and austenite phase fractions on the magnetocaloric and magnetoresistance (MR) properties has been studied across the first-order magneto-structural martensite transition in the polycrystalline Ni45Mn44Sn7In4 Heusler alloy near room temperature. Here, we have studied in detail the structural, calorimetric, magnetic, magnetocaloric, and magneto-resistance properties of the Ni45Mn44Sn7In4 Heusler alloy. The detailed investigation of thermal and magnetic field path dependent magnetization and resistivity reveals that In incorporation in the alloy increases the martensite transition (MT) temperature, magnetocaloric effect (MCE), and MR properties of the sample at relatively low magnetic fields near the room temperature. The temperature and magnetic field path dependent austenite phase fraction have been calculated using a theoretical model. A strong correlation between observed MR and field induced austenite phase fraction (fFIA) has been established, which reveals that MR does not depend on the parent austenite and martensite phases. This work explores the fundamental phenomena of the interplay of austenite and martensite phase fractions that contribute to the magnetocaloric effect (MCE) and MR properties in In doped Ni-Mn-Sn compounds very close to room temperature. The maximum MR is found to be -36.2% for the change in the 8 T magnetic field, when fFIA is 73.9% at 313 K. The isothermal magnetic entropy change, refrigeration capacity, and adiabatic temperature change are found to be 17.5 J kg-1 K-1, 100.8 J/kg, and -7.2 K, respectively, for the change in the 5 T magnetic field near 315 K.
Physics, Astronomy, and Materials Science
© 2020 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics and may be found at https://doi.org/10.1063/5.0028144.
Chabri, T., Kartik Ghosh, D. Mukherjee, and T. K. Nath. "Role of interplay of austenite and martensite phase fractions on the magnetocaloric and magnetoresistance effects across the martensite transition in Ni45Mn44Sn7In4 Heusler alloy near room temperature." Journal of Applied Physics 128, no. 21 (2020): 215106.
Journal of Applied Physics