A perpendicular recording medium having a perpendicular magnetic recording
layer and a magnetically soft underlayer structure disposed beneath the
recording layer. The soft underlayer structure includes at least first
and second soft magnetic layers having different magnetic permeabilities
to create a magnetic permeability gradient in the soft underlayer
structure. One or more of the soft magnetic layers can be anti-parallel
coupled. The soft underlayer structure of the present invention having a
magnetic permeability gradient advantageously leads to reduced adjacent
track erasure (ATE) while maintaining good overwrite (OW) properties.