(ti) / Ni / Of Ti Nanofilm, Microstructure And Magnetic Properties,

The research of magnetic granular films is the focus on magnetism field. The achievement was not only applied to the fields of magnetic recording and sensors etc, but also perfected the theory of micro magnetism. Four series granular films were prepared by dc magnetron sputtering onto glass substrates at room temperature. The microstructures of films were examined by X-ray diffraction (XRD). The morphologies and domain structures were observed by scanning probe micro scope (SPM). And magnetic properties were measured by vibrating sample magnetometer (VSM).It has been found that the microstructure and magnetic properties of (Ti)/Ni/Ti films depend strongly on the Ti under layer, Ti over layer thickness and the Ni magnetic layer thickness at room temperature.X-ray diffraction profiles show that the Ni magnetic layers are formed as the face-center-cubic (FCC) structure. For the series of Ni( 30nm)/Ti( t=1,2,3,4,5nm)film, when the under layer thickness is 3nm, VSM measurements indicate that the out-of-plane coercivity reaches the maximum and SPM image shows that the average grain size is about 19nm.The series of Ti(t=1,3,5,7,10nm)/Ni(30nm)/Ti(3nm) films were prepared by dc magnetron sputtering onto glass substrates at room temperature. VSM measurements indicate that when the over layer thickness is 3 nm, the out-of-plane coercivity reaches the maximum about 450Oe, SPM image shows the average grain size is 20nm. For the Ti (3nm) /Ni (t=5, 10, 15, 20, 25nm) /Ti (3nm) films, we found that when the Ni thickness is 10nm, the coercivity reaches the maximum about 510Oe, and SPM image shows the average grain size is 13nm.It has been found that the microstructure and magnetic properties of Ti (3nm)/Ni (10nm)/Ti (3nm) films depend strongly on the post annealing temperature. Annealed at 400?C, the domain size is the smallest and the coercivity reaches the maximum about 1.5kOe. TheδM curve shows the negative value for the film, which indicates that intergrain-interaction change from exchange-interaction to dipolar-interaction. From XRD profiles and AFM images, it is not attributed to the crystalline anisotropy and the shape anisotropy. The high coercivity of film comes from the stress anisotropy mainly.