Calorimetric investigation of the magnetocaloric effect in Ni sub(45)Co sub(5)Mn sub(37.5)In sub(12.5)

• Published in: Journal of physics. D, Applied physics Applied physics, 2012-06, Vol.45 (25), p.255001-1-7
• Main Authors: Guillou, F, Courtois, P, Porcar, L, Plaindoux, P, Bourgault, D, Hardy, V
• Format: Article
• Language: English
• Subjects: Calorimetry
• ISSN: 0022-3727
• DOI: 10.1088/0022-3727/45/25/255001

A calorimetric investigation of a Ni sub(45)Co sub(5)Mn sub(37.5)In sub(12.5) single crystal has been carried out by combining differential scanning calorimetry (DSC) and heat capacity (C) measurements. The martensitic transition showing a first-order character spread over a wide temperature range, a specific measuring technique of C (T) has been developed. This method--based on a time-resolved analysis of successive heating pulses--was found to yield an entropy change at the transition ( Delta S sub(tr)) that is very close to that derived from DSC. To investigate the magnetocaloric effect, both the isothermal entropy change Delta S sub(T) and the adiabatic temperature change Delta T sub(ad) were derived from heat capacity curves recorded in a series of magnetic fields up to 7 T. The maximum values of Delta S sub(T) (T, B) were observed to be in accordance with those determined from the Maxwell equation. Furthermore, maximum values of Delta T sub(ad) (T, B) resulting from the application of 2 T, 5 T and 7 T were found to be equal to -2.3 K, -6.1 K and -9.4 K, respectively.