Slider dynamic motion during writer-induced head-disk contact

The spatial and temporal characteristics of slider motion resulting from writer-induced pole tip protrusion are studied. Head-disc contact results from protrusion and the amount of contact is varied by varying the steady-state write current, the amount of overshoot, and the write frequency, all of which change the amount of heat dissipated in the writer. We measure the resulting slider motion via three orthogonal LDVs and a position sensitive detector to give five of the six possible degrees of freedom of motion. We compare the relative magnitudes of motion in different directions and we explore how higher power gives more continuous contact. We also investigate the time scales associated with protrusion and with air bearing pitch angle changes. We measure the speed with which the writer protrudes and find that slider pitch angle change increases linearly with the amount of current.