ac technique applied to cp measurements in Ni-Mn-Ga alloys

The specific heats (cp) of two single crystalline ferromagnetic shape memory alloys close to the stoichiometric Ni2MnGa have been measured by the ac technique in both quasi-isothermal and scanning modes. The measurements were carried out in a temperature range slightly broader than the transformation interval of each alloy. This allows getting reliable values of the cp difference between parent and martensite phases within the transformation range, which is important for the thermodynamic analysis of the thermoelastic martensitic transformation undergone by these alloys.