Speaker
Description
Atom probe tomography is frequently employed to characterize the elemental distributionin solids with atomic resolution. Here we review and discuss the potential of this techniqueto locally probe chemical bonds. Two processes characterize the bond rupture in laser-assisted field emission, the probability of molecular ions, i.e. the probability that molecularions (PMI) are evaporated instead of single (atomic) ions, and the probability of multipleevents, i.e. the correlated field-evaporation of more than a single fragment (PME) uponlaser- or voltage pulse excitation. Here we demonstrate that one can clearly distinguishsolids with metallic, covalent, and metavalent bonds based on their bond rupture, i.e. theirPME and PMI values. Differences in the field penetration depth can largely explain thesedifferences in bond breaking. These findings open new avenues in understanding anddesigning advanced materials, since they allow a quantification of bonds in solids on ananometer scale, as will be shown for several examples. These possibilities would evenjustify calling the present approach bonding probe tomography (BPT).
