Wear Measurements for Proximity Recording Heads

A focused ion beam is used to create wear fiduciary marks on subambient pressure air bearing sliders, and both atomic force microscopy and optical profilometry are used for localized wear measurement. Optical profilometry exhibits a σ_e (standard error) of 0.23-0.36 nm compared to 4.2-11.8 nm for the AFM, where the range results from differences in measurement location. Data from both measurement methods are used to examine wear behavior as a function of contact start/stop cycling. A group of test heads is oriented such that wear is expected to occur on an alumina surface at nominal operating speed. Wear results, evaluated by both AFM and optical profilometry, show patterns consistent with the flying attitude of the heads and excellent agreement between the two measurement techniques on the worn parts.