A perpendicular magnetic recording medium adapted for high recording
density and high data recording rate comprises a non-magnetic substrate
having at least one surface with a layer stack formed thereon, the layer
stack including a perpendicular recording layer containing a plurality of
columnar-shaped magnetic grains extending perpendicularly to the
substrate surface for a length, with a first end distal the surface and a
second end proximal the surface, wherein each of the magnetic grains has:
(1) a gradient of perpendicular magnetic coercivity H.sub.k extending
along its length between the first end and second ends; and (2)
predetermined local exchange coupling strengths along the length.