Abstract
Although gold is one of the noble metal with lowest reactivity, dark pits were observed to form on the Au(111) surface in ambient by SPM. Three hypotheses of dark pits formation was provided: 1. single atomic depth vacancy. 2. gold oxides. 3. contaminant-induced product. In order to verify which hypothesis is correct, series of STM and AFM experiments were performed. Though the nature and the formation mechanism of dark pits are still unclear, useful results were provided. Base on our results the hypothesis of gold oxides is most probable.