A laminated perpendicular magnetic recording medium has two recording
layers (RL1 and RL2) that are separated and magnetically decoupled by a
nonmagnetic spacer layer (SL). The SL has a thickness and composition to
assure there is no antiferromagnetic or ferromagnetic coupling between
RL1 and RL2. Thus in the presence of the write field, RL1 and RL2 respond
independently and become oriented with the direction of the write field.
Each RL is an "exchange-spring" type magnetic recording layer formed of
two ferromagnetic layers (MAG1 and MAG2) that have substantially
perpendicular magnetic anisotropy and are ferromagnetically
exchange-coupled by a nonmagnetic or weakly ferromagnetic coupling layer
(CL). The medium takes advantage of lamination to attain higher
signal-to-noise ratio (SNR) yet has improved writability as a result of
each RL being an exchange-spring type RL.