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 smooth disks are studied using laser Doppler vibrometer, friction sensor, acoustic emission (AE) transducer and read back signal from a magnetoresistive head on the slider. When the slider contacts with the smooth disk, friction, AE signal and the amplitude of vibration show a steep increase, although the contact occurs at much lower flying height than the textured disk. Both pitch and roll vibration modes of the slider air bearing are strongly excited with the amplitude of about 10 nm. The pitch vibration results in the slider impacting the disk surface severely, which causes thermal asperities with extraordinary high amplitude.