Atomic Fingerprinting of Heteroatoms Using Noncontact Atomic Force Microscopy

Abstract

Nonetheless, a systematic way to discriminate atomic species is lacking. Here, we extend previous work [12] for the identification of heteroatoms.We employ ab initio real-space pseudopotentials to accurately simulate nc-AFM images of four molecules: DBT, ITP, ACR, and FePc, which contain the heteroatoms S, I, and N. We find S and I atoms can be easily identified from C, which is not surprising given their different atomic structure. We also propose a new method, scanning with a chemically inert tip followed by a chemically active tip, to effectively determine the structures of N containing molecules. We suggest the use of an inert tip, such as a CO tip, to determine the carbon skeleton coupled with the use of a metallic tip, such as a Cu tip, to determine the position of the N atoms.

Observation of electron orbital signatures of single atoms within metal-phthalocyanines using atomic force microscopy

“…Distinguishing atoms that only differ by one nuclear charge using AFM with an inert tip, which only measures the subtle electron density distributions instead of interacting with the specimen chemically [26][27][28] , is extremely challenging. For example, even an HR-AFM (CO tip) can barely distinguish N from C atoms unless a specific treatment is performed 16 . Subatomic structures of single adatoms and small clusters were resolved using HR-AFM 18 .…”

“…In addition, HR-AFM with molecularly functionalized tips has been used for quantitative structural measurements on organic molecules with spectacular atomic resolution 12,13 . Bond order 14,15 and heteroatom 16,17 discrimination, and even real-space imaging of individual atoms 18,19 and intermolecular bonds have been reported 20,21 . These experimental advances have been accompanied by the innovation of…”

Predicting AFM Topography from Optical Microscope Images Using Deep‐Learning

“…Since its inception, atomic force microscopy (AFM) has been ubiquitously used for probing nanoscale surfaces in various domains: biology, [1,2] material science, [3] chemistry, [4] and physics, [5] to name a few. Indeed, its measurement capability in the sub-optical wavelength regime has been paramount to establishing a deeper understanding of each scientific domain.…”