Comparison of atomic force microscopy and transmission electron microscopy of second-phase particles

Abstract

It has been explored whether and to what extent atomic force microscopy (AFM) can be used to determine the size and the volume fraction f of fine (diameter far below 1 μm) second-phase particles. A Cu-0.65at.% Au solid solution strengthened by spherical incoherent SiO₂ particles served as a model system; their average radius r was 50 nm. The procedures for correcting the atomic force micrographs for the finite dimensions of the atomic force microscope tip are detailed. So far the error limits in the AFM determination of f and r exceed those which can be reached by transmission electron microscopy (TEM). AFM yields detailed information on those particles which intersect the surfaces of thin TEM foils. This information is indispensable for the evaluation of TEM images but can only be obtained by AFM or with lower accuracy by replica techniques and scanning electron microscopy.