An embodiment of the invention is a layered magnetic thin film structure
that uses antiferromagnetically coupled (AFC) magnetic layers where the
top layer structure consists of an upper magnetic layer that is weakly
ferromagnetically coupled via a nonmagnetic or weakly magnetic exchange
coupling layer (interlayer) to a ferromagnetic exchange enhancing layer
that is in turn, AF coupled to the lower ferromagnetic layer of the AFC
structure. Preferred materials for the weak coupling layer include alloys
of cobalt such as CoRu, CoBRu and CoCr in which the Co content is below
the point at which the material would be ferromagnetic. A second
embodiment of the invention is a laminated, AF-coupled media structure.
In this structure the lower AFC layer that makes up the lower laminate
layer includes: the middle magnetic layer, the weak ferromagnetic
coupling layer, and the exchange enhancing layer.