5 Gb/in(2) recording demonstration with NiFe/Co90Fe10 spin-valve heads and low-noise thin-film disks

A high areal density of 5 G b/in(2) (7.75 Mbit/mm(2)) has been demonstrated with narrow track NiFe/Co90Fe10 spin-valve read heads on low-noise CoCrTaPt/CrMo-alloy thin film disks. The MFM measurements clearly showed the write track width to be 1.2 mu m on the CoCr17Pt5Ta4 thin-film media. This corresponds to 19.5 kTPI (768 track/mm) including a guard band of 0.1 mu m. The error rate performance was tested using a PR4ML channel with write precompensation. At a data rate of 33 MB/s, a practical error rate of 9.0x10(-6) was obtained without error correction at a linear density as high as 257 kBPI (10.1 kbit/mm). At a linear density of 217 kBPI (8.5 kbit/mm), we obtained an error rate of less than 10(-8) without error correction. With a 192-bit Reed-Solomon error correcting code, we can expected an error rate of 1.0x10(-14).