Oriented longitudinal media on glass substrates

This paper reports on the recent breakthrough of achieving high orientation ratio (OR) on directly textured glass substrates. The authors show the necessary structural conditions to obtain OR on glass substrates. They present a unique design of a medium structure including a seedlayer, an underlayer, and an antiferromagnetically coupled magnetic structure. Such a structure gives rise to a high OR and leads to improved recording performance. In particular, the authors show the significant low-noise benefit of the oriented media with narrow recording heads. This technology has enabled the extension of glass disk media to ultrahigh density longitudinal recording.