Pressure dependence of magneto-structural properties of Co-doped off-stoichiometric Ni2MnGa alloys

A strong effect of pressure on magnetization and paramagnetic moment of the Co-doped Mn-rich Ni50-xCoxMn25+yGa25-y (x = 5,7,9 and y = 5,6,7,8) Heusler alloys is presented and compared with very weak pressure sensitivity of magnetization of the stoichiometric Ni2MnGa alloy. The effects of both, the pressure and the magnetic field, on temperature of the structural martensitic transition in the alloys are discussed with a use of the Clausius-Clapeyron relations. An analysis of pressure and field effects provides a possibility to evaluate structural and magnetic parts of latent heat of the martensitic transitions in the studied alloys. The Curie temperature of martensite phase of the Co-rich alloys is not affected by pressure.