Reiji Nishikawa

Texture-indduced magnetic anistotrophy of Co-Pt films

The induced magnetic anisotropy of Co-Pt films on textured Ni-P-plated Al substrates depended on the Pt content of the films and texturing conditions. The axis of easy magnetization for the Co film was along the texture lines. The surface grains for an anisotropic Co-20at.%Pt film and those for an isotropic film with the same content seemed to have almost the same shapes, and no clear grain boundaries. No elongation of the grains or grain alignment normal to the grooves was observed. The remanent magnetization measured in the circumferential and radial directions was affected strongly by the Pt content, in a similar manner to magnetostriction. >

Inclining columnar structure in Co-Cr films prepared by roll magnetron sputtering

Co-Cr films, sputtered onto continuously transported substrates, exhibit columnar structure bowing according to incident angle variation during deposition. Surface grains were found to be elongated along the substrate moving direction. This factor seems to be related with the relative film motion. The column inclination is well approximated by the incident angle of the atom beam vector sum, considering the incidence probability from the two line target sources. It was found, by analysing the surface grain shapes using a high speed image processor, that the Co-Cr grains exhibited a sharp normal probability distribution in regard to diameter.

Influence of impurity gases on properties of Co–Cr sputtered films

The influence of impurity gases on c‐axis orientation for Co–Cr sputtered films was investigated, using x‐ray diffraction analysis. The O2 partial pressure at which c‐axis orientation begins to decline depends on the Cr content of films. C‐axis orientation for higher Cr content films was not disturbed up to higher O2 partial pressure. Cr plays an important role in protecting films from oxidation during deposition. For c‐axis orientation, N2 had equal influence on different Cr content films, and was more detrimental than O2. Reduction in c‐axis orientation corresponded well to an increase in spacing of c planes with impurity gas addition and was, therefore, attributed to the entrapment of impurity gas into the film. This hypothesis was confirmed in the case of oxygen with Auger microscopy. O2 addition was considered to be advantageous because it suppresses grain growth without damaging c‐axis orientation. Increase in saturation magnetization was observed only for higher Cr content films with O2 addition; a...