A laminated film structure is disclosed comprising multiple ferromagnetic
layers achieving improved data recording performance. A non-magnetic
spacer layer is disposed between an upper ferromagnetic layer and an
antiferromagnetic coupled (AFC) structure. The AFC structure is comprised
of a ferromagnetic layer and an antiferromagnetic slave layer. The
ferromagnetic layer in the AFC structure, referred to as lower
ferromagnetic layer, may contain tantalum to promote chromium segregation
at the grain boundaries to achieve magnetic decoupling of the grains with
relatively thin boundaries, improving medium signal-to-noise ratio while
maintaining good thermal stability of the medium. In some embodiments,
the interlayer is a five-element alloy such as a CoCrPtBTa alloy.