Preparation And Microstructure And Magnetic Properties Of Ni-Mn-In-Co Alloy Thin Films

Ni-Mn-In-Co magnetic shape memory thin films have been deposited on Si(100) substrate by the method of magnetron sputtering technique. The effect of preparation parameters on surface morphology and chemical content of Ni-MnIn-Co alloys thin films has been investigated systematically by means of SEM, AFM, XRD and DSC measurements. Moreover, the magnetic properties of thin film has been studied. The technology of separating thin film and substrates has also investigated.It is found that sputtering technique has remarkable influence on surface morphology and chemical content. The surface roughness of thin film increases with increasing Ar working pressure while decreasing with substrate negative bias voltages. The content of Ni element decreases with increasing sputtering power while decreasing with increasing substrate of substrate negative bias voltages. The content of In element decreases linearly with the increase of substrate negative bias voltage.According to experimental results, the as-deposited Ni-Mn-In-Co thin films are in partially crystallized state. The substrate temperature plays a significant role on microstructure and crystalline behavior. Ni-Mn-In-Co thin films can be fully crystallized through the heating of the substrate.The study of magnetic property shows that the film of Ni-Mn-In-Co exhibits characteristics of ferromagnetism and shows a relatively large saturation magnetization. The film is ferromagnetic at low temperature and is paramagnetic above 340 K.Ni-Mn-In alloy thin films have been fabricated by using magnetron sputtering technique on substrate of Na Cl crystal, PVA, Pyrex and Cr. The freestanding alloy films have been investigated by means of the water-soluble and wet etching through separating film and substrate. The results indicat that using PVA thin film as substrate is a feasible method.