Abstract
For bit-patterned media, media with low remanent magnetization (M-r) and high M-r regions are needed for storing information, which is usually achieved by lithographically defining magnetic and non-magnetic regions. In this work, we have investigated the use of ion beam modification of media surface to define the low and high M-r states using a medium that is at a low M-r state to start with. The low M-r state is achieved by the use of synthetic antiferromagnetic coupling obtained in Co-alloy/Ru/Co-alloy trilayer structured film. Local ion beam modification at 30 keV energy using Ga+ ions was used to create high M-r regions. AFM and MFM observations indicated that patterned regions of low and high M-r can be observed with ion beam irradiation. This technique is a potential method to achieve patterned media without the need of planarization techniques.