Study of Stability of Local Anodic Oxidation on HOPG and Few Layer Graphene Using AFM in Ambient

Local anodic oxidation (LAO) has been performed on highly oriented pyrolytic graphite (HOPG) and few layer graphene (FLG) using contact-mode (CM) atomic force microscopy (AFM) in a controlled humidity chamber. Different types of LAO patterns, namely, protrusion and trench features were observed for different tip speeds under similar conditions of LAO patterning, in both CM and noncontact-mode (NCM) AFM images. Observed LAO patterns show a variation in their dimensions over time. This paper carries out a study performed on the observed changes in dimensions of LAO patterns made on HOPG and FLG over several days, pointing to the dynamics of these LAO patterns. The stability of the LAO patterns on HOPG is compared with that for FLG. LAO patterns on HOPG show a widening and reduction in depth over a day. LAO patterns on FLG show, in contrast, a random variation in the lateral dimension “width” and stabilization in the vertical dimension “depth” over several days.