Structural features and magnetic properties of Co–W films

The structure and magnetic properties of thin polycrystalline Co$_{100-x}$W$_x$ (0 $\le x\le$ 30) films deposited by magnetron sputtering on glass substrates, including those containing buffer layers Ta, W and Ru, have been investigated. It was found that pure Co films are non-single-phase and contain hpc and fcc crystal modifications. Doping leads to an increase in the concentration of the fcc phase and enhance the texture (111), and subsequently to the amorphization of the films. Buffer layers had a certain influence on the depth and concentration localization of these transformations. A characteristic feature of the magnetism of Co-W films is a significant perpendicular component in the macroscopic magnetic anisotropy, which leads to a “trance critical” magnetic state. It was shown that its source was a textured fcc phase, the crystal anisotropy of which was enhanced by the doping of cobalt with tungsten.