Study of stacking fault effect on magnetic anisotropy of CoPtCr-SiO ₂ perpendicular media by synchrotron radiation x-ray diffraction

Thin films of CoPtCr and CoPtCr-Si O2, perpendicular magnetic media materials, were investigated by synchrotron radiation grazing-incidence x-ray diffraction. The analysis of diffraction peaks in a reciprocal space provided the variation of stacking faults as functions of Pt content in these materials. It was found that stacking faults start increasing at 15-20 and 25-30 at. % Pt for CoPtCr-Si O2 and CoPtCr films, respectively. These results can well explain the phenomenon whereby the magnetic anisotropy of CoPtCr-Si O2 increases with an increasing Pt content and decreases above 20 at. % Pt, whereas that of CoPtCr increases up to 30 at. % Pt and then decreases.