Calorimetric and magnetic study for Ni50Mn36In14 and relative cooling power in paramagnetic inverse magnetocaloric systems Academic Article uri icon

abstract

  • © 2014 AIP Publishing LLC. The non-stoichiometric Heusler alloy Ni50Mn36In14 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 fieldinduced 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.

altmetric score

  • 0.25

author list (cited authors)

  • Chen, J., Bruno, N. M., Karaman, I., Huang, Y., Li, J., & Ross, J. H.

citation count

  • 21

publication date

  • November 2014