Dynamics of transient events at the head/disk interface

Slider/disk contacts of nano and pico sliders are investigated using an acoustic emission sensor and a high bandwidth laser Doppler vibrometer (LDV). The following cases are studied: (a) influence of scratch impact on the airbearing stiffness; (b) influence of lubricant thickness on slider dynamics for single bump impacts; (c) influence of lubricant thickness on slider vertical stick-slip vibrations; (d) dynamics of take-off and landing. Linear time frequency analysis is applied to study simultaneously the impact response of the airbearing and the slider torsional and bending modes. The contact dynamics of single bump impacts is examined as a function of disk velocity and lubricant thickness. Increased slider vibrations are found for thick lubricant films both for sliding contacts as well as for single bump impacts. During the transition from sliding to flying a change of the bending mode frequency is observed. (C) 2001 Elsevier Science Ltd. All rights reserved.