IMPROVEMENT OF CRYSTALLINITY OF Co-Cr AND Ni-Fe LAYERS MEDIA BY USING Co₇₉Cr₂₁ ULTRA THIN UNDERLAYER AND INTERLAYER

Abstract

  The 100Å-thick Co₇₉Cr₂₁ underlayer was helpful not only for improving the crystallinity of Ni-Fe backlayer deposited on the underlayer, but also the c-axis orientation of Co₈₃Cr₁₇ recording layer on the backlayer through an hetero-epitaxial growth between fcc-(111) of Ni-Fe crystallites and hcp-(002) of Co-Cr ones. Electron beam diffractometry and TEM observation for them indicated that Co-Cr ultra thin layer with higher Cr content is suitable as a seed layer to improve crystallinity of upper layers, such as Co-Cr layer and Ni-Fe layers deposited on it. The Co₇₉Cr₂₁ ultra thin layers were used as the interlayer between Co₈₃Cr₁₇ recording layer and Ni₈₁Fe₁₉ backlayer to improve the crystallinity and magnetic properties of these media.