Reproduced Dot Image of Nitrogen Ion Implanted Co/Pd Bit Patterned Media With Flying Head

We investigated switching and read/write (R/W) characteristics of head flyable (Co/Pd) multilayer bit patterned media (BPM) fabricated by ion implantation. Two-dimensional (2-D) signal mapping of the dc magnetized media shows a clear image of 134 Gbit/in
²
dots (60 nm× 80 nm pitch, 28 nm dot size). We performed synchronized writing with individual bits with alternate polarity (ac magnetized) and 2-D mapping of 134 Gbit/in
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patterns. The results substantiated the potential of the fabrication technique. From the read-back signal amplitude, we estimated the effective dot size as 24 nm, slightly smaller than the expected value. We discuss R/W properties and important characteristics such as glide height and magnetic structure of BPM.