title: Influence of nuclear quantum effects on frozen phonon simulations of electron vortex beam HAADF-STEM images.
abstract: We have evaluated atomic resolution high-angle annular dark field images with ordinary beams and electron vortex beams for thin crystals of bcc iron, explicitly considering the atomic vibrations using molecular dynamics. The shape of the image representing an atomic column depends on the orbital angular momentum, sample thickness and temperature. For electron vortex beams we observe characteristic doughnut-shaped images of atomic columns. It is shown how the thermal diffuse scattering reduces the depth of their central minima, which get further smeared by finite source size effects. In addition, it is shown that in calculations of HAADF-STEM images at low temperatures one has to explicitly consider the nuclear quantum effects (zero point vibrations), otherwise the effect of atomic vibrations is strongly underestimated.
authors: Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden.
authors: André
authors: A
authors: Löfgren
authors: Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden.
authors: Paul
authors: P
authors: Zeiger
authors: Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden.
authors: Vancho
authors: V
authors: Kocevski
authors: Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden. Electronic address: jan.rusz@fysik.uu.se.
authors: Ján
authors: J
authors: Rusz
keywords: Electron vortex beams; Frozen phonons; HAADF; Multislice; Nuclear quantum effects; STEM