Embodiments in accordance with the present invention provide a
perpendicular recording medium with low noise and high recording density
by reducing the effects from noise generated from the vicinity of the
interface with the intermediate layer of the recording layer, in a
perpendicular recording medium utilizing a granular recording layer
containing oxygen or oxide additive in a cobalt-chromium alloy formed on
an intermediate layer with a ruthenium or ruthenium alloy layer. A first
recording layer and a second recording layer are formed in order on an
intermediate layer of ruthenium or ruthenium alloy. The first recording
layer and the second recording layer are comprised of cobalt as the main
material in a granular structure containing chromium and oxygen. The
saturation magnetization of the first recording layer is lower than the
saturation magnetization of the second recording layer. When a first
recording layer saturation magnetization is set as Ms1(emu per cubic
centimeter), a second recording layer saturation magnetization is set as
Ms2(emu per cubic centimeter), and the first recording layer film
thickness is set to t1 (nm), then (Ms2-Ms1).times.t1 will be larger than
0 (memu per square centimeter) and smaller than 0.15 (memu per square
centimeter).