AFM imaging analysis of nanoindentation-induced plastic strain in indium surface for calibrating nanoindenters area profiles

Abstract

Atomic Force Microscopy (AFM)-nanoindentation is one of the most popular techniques for characterizing the nanomaterials' mechanical properties. A good calibration of the indenter area profile is essential to achieve quantitatively reliable calculations of these properties. Accurate profile estimation is particularly critical to minimize uncertainties in key mechanical properties like hardness and elastic modulus. In this work, we report the use of indium as a potential candidate for assessing the nanoindenters’ area profiles by imaging analysis of nanoindentation-induced plastic footprints. AFM-nanoindentation technique was particularly used for inducing plastic strain. A systematic and rigorous profiles study was carried out at the apex neighborhood, considering heights lower than 200 [nm] for an accurate estimation at the nanoscale. Results suggest that this methodology is useful to characterize the indenter real geometry shape at the nanoscale, representing a “fast” and low-cost alternative to other popular imaging methods like those based on electron microscopy techniques.