Effect of underlayers of laser-assisted magnetic recording media on high-density recording

The effect of underlayers of laser-assisted magnetic recording media has been investigated from the view point of high-density magnetic recording. The frequency response of a carrier-to-noise ratio (C/N) was measured in the media with various kinds of underlayers. It was found that they affect the high-frequency recording capability; the C/N at higher frequencies has been drastically improved for an Al-underlayered recording medium and a C/N of 40 dB was obtained at a recording frequency of 45 MHz and a track width of 0.35 mum. These results are explained by the surface morphology of the underlayer and its pinning effect on the domain-wall motion that is considered to work well for recording smaller stable domains. (C) 2002 American Institute of Physics.