STRUCTURAL INHOMOGENEITIES IN Co-Cr LAYERS AND THEIR INFLUENCE ON THE MAGNETIC PROPERTIES C.P.G. SCHRAUWEN, .f.P.C. BERNARDS

Structural inhomogeneities are observed in RF sputtered C079Cr21 layers, studied for perpendicular magnetic recording. The effective perpendicular anisotropy is strongly affected by the occurrence of inhomogeneities in the growth direction (e.g. an initial layer), which can be diminished by changing the substrate or by using a Ge underlayer. Lateral inhomogeneities (e.g. due to segregation) have a large impact on the coercivity of the layers and are strongly affected by the substrate temperature during deposition. The substrate temperature is observed to increase steeply at the start of the deposition (20-40 0c). This increase depends on the sputtering power. The further evolution of temperature is dominated by the substrate holder. The thermal contact between substrate and holder can be established reproducibly.