Stress and stress anisotropy in Co-Cr magnetic thin films deposited by magnetron sputtering

In this experiment, the study of stresses in pure Co films as well as in Co-Cr alloy films (12.2-22.0 at.% Cr) was carried out. In addition, the stress anisotropy induced by the magnetostrictive effect was also discussed. It was found that the stresses are all tensile under various deposition conditions, and the stress in the pure Co films is smaller than that in the Co-Cr films. The structural defects elimination model was proposed to explain qualitatively the origin of the stress as well as its dependences on deposition conditions, and the effect of Cr content on the formation of the c-axis preferred orientation of crystallines in Co-Cr films was analyzed. The contribution of the stress anisotropy to the total perpendicular magnetic anisotropy is only 6-9%. The latter originates mainly from the magnetocrystalline anisotropy and the interior shape anisotropy caused by the columnar grain structure.