Studies On Microstructures And Magnetic Properties Of Fe-Co Thin Film For High Density Magnetic Recording Write-head

With the rapid development of the high density recording, it is required that the magnetic head materials have very high coercivity and saturation magnetic flux density. Fe-Co alloys have been intensively investigated because of their very high saturation flux density. Sputter deposited Fe-Co films, however, generally show high coercivity and they are therefore not applicable as the right pole materials in a magnetic recording head.In this thesis, some series of films were prepared by dc magnetron sputtering onto glass substrates at room temperature. Microstructures of films were examined by X-ray diffraction (XRD). Morphologies and domain structures were observed by scanning probe microscope (SPM). And magnetic properties were measured by vibrating sample magnetometer (VSM). The influence of sputtering parameter on their microstructure and magnetic properties were studied, respectively.(1) For the Fe₅₀Co₅₀ (50nm) film, the coercivity of the sample reduces with the substrate temperature increasing. The coercivity reaches the minimum 47Oe for the Fe₅₀Co₅₀ (50nm) film at the substrate temperature of 500?C. SPM image shows the superficial average roughness increases with the substrate temperature increasing. The strength of the sample tested by XRD increases with the substrate temperature increasing.(2) It is found that for the Fe₅₀Co₅₀ films sample, when film thickness was less than 33 nm, the coercivity of Fe₅₀Co₅₀ films reduces with the film thicknesses increasing; The minimum value of coercivity is obtained when the thickness of Fe₅₀Co₅₀ films was 25Oe. When film thickness exceedes than 33 nm, the coercivity of Fe₅₀Co₅₀ films increases with the film thicknesses increasing; The coercivity reaches its peak value 106Oe when its thickness is 170mm. The strength of the peak of the XRD tested sample increases with the thickness of the film increasing.(3) From the study of Fe₇₀Co₃₀ films series, it is found that the coercivity of the sample increases gradually with the thickness while the magnetic saturation decreases. The superficial average roughness increases with the thickness of the films. The strength of the peak of the XRD tested sample increases with the thickness of the film increasing.(4) For the Fe₇₀Co₃₀ membrane sample with annealing temperature 600?C, the coercivity first increases and then reduces with the film thicknesses increasing. The superficial average roughness and magnetic domain increases more and more. The strength of the peak of the XRD tested sample increases with the thickness of the film increasing.