  Homogeneous freestanding films have been obtained by the direct current (DC)
magnetron sputtering technique using a sacrificial layer. After annealing, the
films are crystallized with a strong out-of-plane texture along the (022)
direction. The stoichiometry of the annealed films is close to the target
composition and leads to a martensitic transformation around 255K. The annealed
films demonstrate ferromagnetic behavior with a Curie temperature of about
362K. The magnetization process has been studied on the both states and during
the martensitic transition. The saturation magnetizations have been determined
by fitting the experimental data with a saturation approach law in the range
1-5T. Results show the saturation magnetization of the martensite is around 10%
higher than that of the austenite. A model based on intrinsic magnetic
properties of each state allowing the description of the magnetization M=f (H,
T) of such polycrystalline films during the martensitic transformation is
presented. The mass fraction of martensite inside the austenite phase can be
determined using this model. The shape memory effect is analyzed both by
scanning electron microscopy and by optical microscopy with in-situ measurement
of the resistance temperature dependence.
