Tribo-magnetics and nanometer spaced head-disk systems

As technology moves toward 5~7 nanometer spaced head-disk systems for high density magnetic recording, the mechanical interaction between head-slider and disk-media will strongly affect the magnetic integrity of magnetic head-disk systems. It is time to pay more attention to the study of the relationship among magnetic data on disk media, readback signal from magnetic head, and mechanical interaction between head-slider and disk-media. Therefore, the concept of tribo-magnetics is proposed in this work to study the relationship between mechanical interaction in head-disk interface and the magnetic performance of the magnetic head-disk systems. The work reported in this paper covers 3 major parts of tribomagentics: tribo-decay, tribe-noise and tribomagnetic testing. Results indicate that head-disk interaction can disturb the stability of the recorded magnetic transitions and lead to a decay of readback signal-tribo-decay. Furthermore, the MR/GMR heads are sensitive to the energy transferring between head and disk when the head interacts mechanically with disk media. As a result, tribo-noise will be generated and the reading capability of the head will be affected. Head-disk spacing is one of the most important head-disk interface parameters. The relationship between head-disk spacing and the read/write performance of the head-disk system can he used to characterize the dynamic variation of head-disk interface. Two new methods are reported in this work to increase the testing sensitivity and the testing range of in-situ measurement of the head-disk spacing, including a triple harmonic method for high sensitivity in-situ measurement and a scanning carrier current method for load/unload applications which requires larger testing range