title: Laser-Assisted Field Evaporation and Three-Dimensional Atom-by-Atom Mapping of Diamond Isotopic Homojunctions.
abstract: It addition to its high evaporation field, diamond is also known for its limited photoabsorption, strong covalent bonding, and wide bandgap. These characteristics have been thought for long to also complicate the field evaporation of diamond and make its control hardly achievable on the atomistic-level. Herein, we demonstrate that the unique behavior of nanoscale diamond and its interaction with pulsed laser lead to a controlled field evaporation thus enabling three-dimensional atom-by-atom mapping of diamond (12)C/(13)C homojunctions. We also show that one key element in this process is to operate the pulsed laser at high energy without letting the dc bias increase out of bounds for diamond nanotip to withstand. Herein, the role of the dc bias in evaporation of diamond is essentially to generate free charge carriers within the nanotip via impact ionization. The mobile free charges screen the internal electric field, eventually creating a hole rich surface where the pulsed laser is effectively absorbed leading to an increase in the nanotip surface temperature. The effect of this temperature on the uncertainty in the time-of-flight of an ion, the diffusion of atoms on the surface of the nanotip, is also discussed. In addition to paving the way toward a precise manipulation of isotopes in diamond-based nanoscale and quantum structures, this result also elucidates some of the basic properties of dielectric nanostructures under high electric field.
authors.affiliation: Department of Engineering Physics, École Polytechnique de Montréal , Montréal, C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada.
authors.forename: Samik
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Correlated Electronics Group, Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Materials Science and Engineering and Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University , Evanston, Illinois 60208-3108, United States.
authors.forename: Dieter
authors.initials: D
authors.lastname: Isheim
authors.affiliation: Department of Materials Science and Engineering and Northwestern University Center for Atom-Probe Tomography (NUCAPT), Northwestern University , Evanston, Illinois 60208-3108, United States.
authors.forename: David N
authors.initials: DN
authors.lastname: Seidman
authors.affiliation: Department of Engineering Physics, École Polytechnique de Montréal , Montréal, C. P. 6079, Succ. Centre-Ville, Montréal, Québec H3C 3A7, Canada.
authors.forename: Oussama
authors.initials: O
authors.lastname: Moutanabbir
keywords: Diamond; atom probe tomography; chemical vapor deposition; dielectric nanostructure; field evaporation; stable isotopes