Photoelectron Holography Of Platinum (111) (original) (raw)

Photoelectron holography of Pt ( 111 ) at 351 eV

Chemical Physics Letters, 1993

A 351 eV photoelectron hologram of a Pt (11 I) surface was collected by detection of photoelectrons from the 4fs,, subshell in a display analyzer, and was Fourier-analyzed. The real space image showed sensitivity to the fourth atomic layer, excellent reproduction of the fee lattice, and sixteen source-atom neighbors. Transverse atomic positions were located to 0.1 A. Photoelectron holography is thus shown to be capable of imaging lattices and interfaces, using low-energy electrons.

Differential Photoelectron Holography: A New Approach for Three-Dimensional Atomic Imaging

Physical Review Letters, 2002

We propose differential holography as a method to overcome the long-standing forward-scattering problem in photoelectron holography and related techniques for the three-dimensional imaging of atoms. Atomic images reconstructed from experimental and theoretical Cu 3p holograms from Cu(001) demonstrate that this method suppresses strong forward-scattering effects so as to yield more accurate three-dimensional images of side- and back-scattering atoms.

Optimal atomic imaging by photoelectron holography

Journal of Electron Spectroscopy and Related Phenomena, 1997

Several recent papers have dealt with the question of whether large-scale photoelectron diffraction data spanning a significant range in both angle and wavenumber can be analyzed as holograms so as to produce directly three-dimensional images of near-surface atomic structure. Data are thus taken over some volume in the photoelectron wavevector k-space, and then transformed to obtained atomic images. In this work, we review four analysis methods proposed to date for deriving atomic positions directly from photoelectron diffraction data and consider the application of them to theoretical diffraction patterns calculated from various single-scattering model clusters. This permits some general conclusions as to domains of applicability and the optimization of k-space sampling so as to minimize data acquisition time, while still assuring atomic images that are free of coarse k-sampling aberrations. We conclude that holographic imaging of atoms does not require exceedingly large photoelectron diffraction data sets, with a few thousand data points being a suitable minimum, and we also comment on the relative merits of the four different imaging algorithms. ᭧ 1997 Elsevier Science B.V.

Photoelectron holography applied to surface structural determination

1995

Co-Chair Professor Charles B. Harris, Co-Chair Photoemitted electron waves are employed as coherent source waves for angstrom-scale holographic imaging of local atomic geometry at surfaces. Electron angular distribution patterns with a specific electron kinetic energy are collected above a sample surface and serve as a record of the interference between the source wave and the waves scattered from surrounding ion cores. Upon application a mathematical imaging

Atomically Resolved Images from Near Node Photoelectron Holography Experiments on Al(111)

Physical Review Letters, 2001

Szöke's concept for electron holography is hampered by forward scattering that dominates electron diffraction from electron point sources below the surface top layer. Forward scattering was proposed to be suppressed if the anisotropic nature of the electron source wave is exploited [T. Greber and J. Osterwalder, Chem. Phys. Lett. 256, 653 (1996)]. Experiments show a strong suppression of forward scattering in Al if Al 2s photoelectrons ͑E kin 952 eV͒ are measured near the nodal plane of the outgoing p wave. The holographic reconstruction from such diffraction data provides three dimensional images of atomic sites in unit cells with a size of more than 10 Å.

Holographic images of Pt(111) using Kikuchi electron diffraction

Physical Review B, 2002

Three-dimensional atomic images of a Pt͑111͒ surface are obtained by direct inversion of multiple lowenergy Kikuchi electron-diffraction patterns. The images are in the backscattering direction, and the positions of the images are consistent with those expected from the atomic structure near the Pt͑111͒ surface. The strong electron scattering of the Pt atoms causes no observable problems in the Kikuchi electron holography.

Photoelectron holography of atomic targets

Physical Review A, 2019

We study the spatial interference effects appearing during the ionization of atoms (H, He, Ne, and Ar) by few-cycle laser pulses using single-electron ab initio calculations. The spatial interference is the result of the coherent superposition of the electronic wave packets created during one half cycle of the driving field following different spatial paths. This spatial interference pattern may be interpreted as the hologram of the target atom. With the help of a wave-function analysis (splitting) technique and approximate (strong-field and Coulomb-Volkov) calculations, we directly show that the hologram is the result of the electronic-wave-packet scattering on the parent ion. On the He target we demonstrate the usefulness of the wave-function splitting technique in the disentanglement of different interference patterns. Further, by performing calculations for the different targets, we show that the pattern of the hologram does not depend on the angular symmetry of the initial state and it is strongly influenced by the atomic species of the target: A deeper bounding potential leads to a denser pattern.

Holographic atom imaging from experimental photoelectron angular distribution patterns

1993

Thisis a preprintof apaperintendedforpublication in ajournalorproceedings. Since changes may be made before publication, this preprintis made available with the understandingthat it will not be cited orreproducedwithout the permission of the author. MASTE/ Ir, frRl_OTlOfl OFTHiSOOCRMENT [$[J_i_[IJ_O o DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responslbilitT for the accuracy, completeness, or usefulness of any information, apparatus, prod_m, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Governlaent or the University of California. The views and opinions of authors expr_sed herein do not necessarily state or reflect those of the United States Government or the University of California, and shah not be used for advertising or product endorsement purposes.

Photoelectron and x-ray holography by contrast: enhancing image quality and dimensionality

2001

Abstract Three forms of electron or x-ray holography 'by contrast'are discussed: they all exploit small changes in diffraction conditions to improve image quality and/or extract additional information. Spin-polarized photoelectron holography subtracts spin-down from spin-up holograms so as to image the relative orientations of atomic magnetic moments around an emitter atom.