Abstract
Durability of a Co-Cr perpendicular magnetic recording medium is studied with regard to its macroand microscopic surface profiles. Macroscopic deformation of medium caused by head sliding is investigated with a newly developed measurement system which uses laser light. Also, microscopic topography of the medium is estimated by spectral analysis of surface profile data. These are used for observation in head sliding. The medium starts to wear at the sites of protuberances, and the worn portions scratch the medium surface severely. It has been found that the period of durability before deformation of medium is entirely dependent on the initial profile. When the microscopic surface roughness of medium is so uniform that extraordinary protuberances cannot be observed, the macroscopic medium profile never changes during a period of examination of 72000 passes, suggesting a more durable medium.
