Magnetic properties of ferromagnetic shape memory alloys Ni _{2-x} Cu _{x} MnGa

Abstract

Magnetic measurements on Ni _{2-x} Cu _{x} MnGa with 0 ≦ x≦ 0.8 are made in the temperature range between 4.2 K and 440 K. A phase diagram of Ni _{2-x} Cu _{x} MnGa is determined from the results of the temperature dependence of the initial permeability. The Curie temperature T_{C} increases with the Cu concentration x. The martensitic and reverse martensitic transformation temperatures decrease abruptly with x. It is deduced that the substitution for Ni by Cu in Ni _{2} MnGa promotes to localize the magnetic moment of Mn atom.