Demonstration of 500 megabits per square inch with digital magnetic recording

The authors describe the testing and modeling methods undertaken to demonstrate and verify an areal density of 500 Mb/in² with a combined inductive, thin-film write head and a magnetoresistive read head on an advanced, state-of-the-art thin-film disk. The linear density was 100000 bit/in (3937 bit/mm), the track density was 5000 tracks/in (196.9 tracks/mm), and the flying height was 2.5 μin (64 nm). The components were characterized in great detail, including write, read, erased-band, and read-profile skirt widths. A combination of off-track measurements and the track density error rate model showed that the target density was obtained for a soft error rate of 10^-6 and a TMRw/r (write-to-read track misregistration) of 30.8 μin (782 nm)