High coercivity Co-alloy thin films on polymer substrates

Films of (101~0) textured CoCrPt have been sputtered on polymer substrates for use as thin film tape media. Underlayers of NiAl combined with various intermediate layers were employed to obtain this orientation without thermal damage to the polymer. It was found that NiAl underlayers sputtered on tape substrates have a [112] growth texture, like they do on glass. Film coercivity varied as a function of intermediate layers used, with the highest value of coercivity (3800 Oe) being obtained with a composite intermediate layer of CrMn/CoCrMn. TEM observation showed that the CoCrMn component of these intermediate layers was hexagonal with a (101~0) texture and low stacking fault density. The CoCrPt layers deposited on these CoCrMn layers had uniform grains with a lower stacking fault density, possibly due to grain-to-grain epitaxial growth of CoCrPt on CoCrMn.