Atomic force microscopy of magnetic rigid disks and sliders and its applications to tribology

Abstract

Surface topography measurements of magnetic rigid disks and a slider are made using an atomic force microscope (AFM) and a conventional noncontact optical profiler (NOP). The lateral resolution for the surface topographs spans the range of 1 μm down to 2 nm. Topography measurements are used to predict summit statistics and the real area of contact statistics. We find that contact statistics predictions are a strong function of the lateral resolution of the roughness measurement tool. As the magnetic slider comes into contact with the disk surface, the nanoasperities (detected by AFM) plastically deform instantly and subsequently the load is supported by the elastic deformation of microasperities (detected by NOP). AFM also allows the measurements of lubricant-thickness distributions on smooth surfaces. Examples for magnetic disks are presented.