Journal of Thermal Analysis and Calorimetry

, Volume 113, Issue 2, pp 859–863

Effect of composition on the thermal behavior of NiMnGa alloys

Authors

    • Department of Physics Elazig, Faculty of ScienceFirat University
  • Yıldırım Aydoğdu
    • Department of Physics, Faculty of ScienceGazi University
Article

DOI: 10.1007/s10973-012-2817-1

Cite this article as:
Kök, M. & Aydoğdu, Y. J Therm Anal Calorim (2013) 113: 859. doi:10.1007/s10973-012-2817-1

Abstract

The methods to determine martensitic transformation temperature, enthalpy and entropy change, specific heat capacity change with temperature, and transformation activation energies of Ni–%29.5Mn–%21Ga, Ni–%29Mn–%21Ga, Ni–%29.5Mn–%20Ga, and Ni–%28.5Mn–%20.5Ga (atomic percentage) alloys were investigated by differential scanning calorimetry. It was observed that the transformation temperature increased with an increase in atomic nickel ratio. Meanwhile, it was detected that the change in enthalpy increases with the amount of nickel. The highest values of entropy change and the heat capacity at room temperature were observed in the alloy having the least amount of nickel in it.

Keywords

NiMnGa shape memory alloysThermal behaviorEntalpy changeEntropy changeSpecific heat capacity

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2012