Diffusion analyses of non-ferromagnetic element in the cap-layer of post-annealed CoCrPt perpendicular media

This paper reports on the factors that dominate diffusion phenomena in post-annealed CoCrPt media with various cap-layer elements X. Hf- and Zr-capped media were found to show low diffusion temperature and have thin reacted layer in this experiments. These results are explained with following relationships revealed by detailed analyses of boundary diffusion and interdiffusion: 1) X with high melting point in cap-layer hardly starts boundary diffusion and interdiffusion, 2) X-capped media with higher melting point of CoX compound forms thinner reacted layer, and 3) X with low enthalpy of Co-X formation lead to low diffusion temperature.