A perpendicular magnetic recording medium comprises a layer stack formed
over a surface of a non-magnetic substrate, and comprising, in overlying
sequence from the surface: a magnetically soft underlayer; an interlayer
structure for crystallographically orienting a layer of a perpendicular
magnetic recording material formed thereon; and at least one
crystallographically oriented, magnetically hard, perpendicular magnetic
recording layer on the interlayer structure; wherein the interlayer
structure is a triple-layer stacked structure comprising: a first
interlayer of a first non-magnetic material proximal the magnetically
soft underlayer and containing Ru; a second interlayer of a second
non-magnetic material in overlying contact with the first interlayer and
not containing Ru; and a third interlayer of a third non-magnetic
material in overlying contact with the second interlayer and containing
Ru.