A study of magnetic recording media on glass substrates

Magnetic media deposited on glass substrates with metal seedlayer, Cr underlayer and CoCrPtTa alloy were studied. Within each group of samples, although the bulk magnetic properties were made to be similar, the media noise differed significantly; microstructural study indicated that the grain sizes of the magnetic layers were similar. X-ray diffraction study indicated that the magnetic layer was mostly {10.0} textured, with some [00.2] and [10.1] oriented grains also present. A correlation was observed between stronger CoCrPtTa {00.2} diffraction peak and lower media noise; the Cr {200} peak in the lower noise media was also much weaker. The different crystallographic texture is likely promoted by the surface condition of the seedlayer; larger number of [00.2] grains within the mostly {10.0} textured magnetic layer may suppress the formation of large coherently-magnetized regions in the zig-zag transitions, which mould result in lower media noise