Atomic Observation on Diamond (001) Surfaces with Near-Contact Atomic Force Microscopy

Achieving atomic-level characterization of the diamond (001) surface has been a persistent goal over recent decades. This pursuit aims to understand the smooth growth of diamonds and investigate surface defects and adsorbates relevant to applications. However, the inherently low conductivity and the short C-C bonds present significant challenges for atomic resolution imaging. Here, we successfully addressed these challenges using near-contact atomic force microscopy with reactive Si tips, achieving atomic resolution, even at room temperature. Density-functional-theory calculations revealed that the formation of tilted Si-C bonds between scanning probes and surfaces, coupled with the reordering of surface C-C dimers, are critical factors for achieving atomic resolution. Beyond surface characterization, these advancements in atomic-resolution microscopy are poised to drive future progress in diamond technologies, facilitating the identification of dopants and the construction of artificial nanostructures.