Switching field distribution of FePt-C/FePt exchange coupled perpendicular media

摘要

Since the grain size of the recording media has to be reduced, a magnetic material with high Ku must be applied for the concern of thermal stability. However, high K_u media require high writing field in order to write the information onto the media. Due to the physical limitation where the maximum attainable head field is about 1.7 T, the writability of such media becomes a challenge. In this work, by increasing FePt soft layer thickness in FePt-C/FePt exchange coupled granular/continudus (CGC) perpendicular media, we successfully reduced the coercivity field from 4.9 to 1.4 T without sacrificing thermal stability. Meanwhile, the switching field distribution (SFD) of the bilayer media also got significant improved. Both of these advantages make FePt-C/FePt CGC media here a potential candidate for extremely high areal density recording media which is writable meanwhile thermal stable.