| Thin film of 18,20 and 25at%Ni-Co were prepared by vacuum evaporation technique. The composition and structure of the film and the resulting magnetic properties such as saturation magnetization, magnetic anisotropy and coercive force, have been studied systematically. The microstructure of the films is a mixture of hcp and fcc phases. The saturation magnetization and coefficients of magnetic anisotropy K_(2θ) and K_(46) decr ease with Ni content, while the coercive force increases. The easy axis of magnetization of thin films is parallel to the surface of films. The coercive force strongly depends on the thickness of films, and reaches maximum value at the thickness of about 0.18㎛. The coercive force increases when the films are held at 300℃ for an hour. However, the saturation magnetization is not changed by the heat treatment. |
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