Evaluation of Double-Layered Magnetic Recording Medium Composed of Perpendicular and Longitudinal Anisotropy Layers

A double-layered (DL) medium composed of a CoNiReP perpendicular anisotropy top layer (0.20 µ m thick) and CoP longitudinal anisotropy underlayer (0.05 µ m thick) was fabricated and its recording characteristics were investigated with a combination of a ring-type head. The reproduced voltage of the DL medium was enhanced to be larger than that of the simple summation of the reproduced voltage of the CoNiReP single-layered medium and that of the CoP one. Moreover, the reproduced waveform of the DL medium showed a single peak pulse and it did not change even at higher recording magnetomotive force (MMF). These results suggest that the reproduced voltage enhancement comes from the phase synchronization effect even at higher recording MMF.