Structural And Magnetic Properties Of Ni-Mn-Sn Thin Films

We report a systematic investigation of structural and magnetic properties of Mn-rich off-stoichiometric nano-crystalline Ni48.84Mn37.96Sn13.20 ferromagnetic shape memory alloy thin films, grown on Si (100) substrates at ambient temperature by dc magnetron sputtering. As-deposited films were amorphous in nature. Crystallization was induced progressively when the amorphous films were heat treated at elevated temperatures. 1 h of annealing at 375 degrees C was sufficient to induce crystallization of the stable L2(1) phase. As-deposited amorphous films were paramagnetic in nature. They became progressively ferromagnetic as crystallinity developed in the films with increase in annealing temperature. By varying deposition time for a set of pre-fixed process parameters, the film thickness was varied. Magnetic property of the films showed variation with film thickness. The easy axis of magnetization was along the film plane direction.