Isotope analysis in the transmission electron microscope

Abstract

The Ångström-sized probe of the scanning transmission electron microscope can visualize and collect spectra from single atoms. This can unambiguously resolve the chemical structure of materials, but not their isotopic composition. Here we differentiate between two isotopes of the same element by quantifying how likely the energetic imaging electrons are to eject atoms. First, we measure the displacement probability in graphene grown from either ${}^{12}$C or ${}^{13}$C and describe the process using a quantum mechanical model of lattice vibrations coupled with density functional theory simulations. We then test our spatial resolution in a mixed sample by ejecting individual atoms from nanoscale areas spanning an interface region that is far from atomically sharp, mapping the isotope concentration with a precision better than 20%. Although we use a scanning instrument, our method should be applicable to any atomic resolution transmission electron microscope and to other low-dimensional materials.

35 pages, 6 figures, 1 table

References in corpus (6)

• Mid-infrared plasmons in scaled graphene nanostructures
• The phonon dispersion of graphite by inelastic x-ray scattering
• Localized atomic basis set in the projector augmented wave method
• Stone-Wales--type transformations in carbon nanostructures driven by electron irradiation
• Silicon-carbon bond inversions driven by 60 keV electrons in graphene
• Towards weighing individual atoms by high-angle scattering of electrons

Cited by in corpus (5)

• Manipulating low-dimensional materials down to the level of single atoms with electron irradiation
• Single-atom spectroscopy of phosphorus dopants implanted into graphene
• Towards atomically precise manipulation of 2D nanostructures in the electron microscope
• Unraveling the 3D atomic structure of a suspended graphene/hBN van der Waals heterostructure
• Buckyball sandwiches