In a double layered perpendicular magnetic recording medium, recording reso
lution and time decay of output signal have been studied. Introduction of a
stacked intermediate layer (NiFeNb/Ti) between a soft magnetic back layer
and a storage layer improves magnetic property of the storage layer. The st
acked intermediate layer can reduce the initial growth layer of the storage
layer by hetero-epitaxial growth. Time decay of output signal for a medium
with the stacked intermediate layer was suppressed within -0.4 dB at 1000
seconds after recording at 100 kFRPI. A reproduced signal at an extremely h
igh linear density of 950 kFRPI has been confirmed by a CF-SPT head for wri
ting and a GMR head with track width of 0.4 micrometer for reading.