Magnetic disk unit having magnetic disks and a magnetic head with a head slider which is in contact with surfaces of the magnetic disks

摘要

A magnetic disk includes a non-magnetic substrate with a surface processed layer having fine irregularities formed at least on a main surface thereof, and at least a thin film magnetic film and a protective film formed in that order on the non-magnetic substrate in such a manner that the fine irregularities are duplicated thereof. The surface of the surface processed layer of the non-magnetic substrate has protrusions whose surfaces are made flat and a configuration which exhibits a three-dimensional bearing curve in which the bearing ratio at a section taken at a depth from the top of the surface which corresponds to the portion of the top portion deformed by the head load during the contact start-stops drive is between 0.1% and 10%. The protrusions formed on the surface processed layer have a height ranging from several nm to several tens of nm. The bearing ratio is a value obtained at a depth of 5 to 10 nm from the top of the protrusions.