Slider dynamics during continuous contact with textured and smooth disks in ultra low flying height

Dynamics of a nano-slider during continuous contact with textured and smoot h disks are studied using laser Doppler vibrometer, friction sensor, acoust ic emission (AE) transducer and read back signal from a magneto-resistive h ead on the slider. The flying height of the slider is controlled from flyin g to contact at the same velocity by changing the environmental pressure. W hen the slider flies over the textured disk, contact occurs at flying heigh t of 14 nm, and friction and AE signal increase gradually with decreasing f lying height. The increase in the amplitude of the slider vibration is with in a few nanometers from flying to contact. When the slider flies over the smooth disk, contact occurs at much lower flying height of 6 nm, However, f riction, AE signal and the amplitude of the vibration show a steep increase upon contact. Both pitch and roll vibration modes of the slider air bearin g are strongly excited with the amplitude of about 10 nm, The pitch vibrati on results in the slider impacting the disk surface severely. As the result . the disk vibrates at the same frequency. In addition, thermal asperities with extraordinary high amplitude are observed associated with the impacts induced by the pitch vibration.