Many-body and QED effects in electron-atom inelastic scattering in EELS

Abstract

The elemental composition and electronic structure of materials analyzed by electron energy loss spectroscopy (EELS) are probed by the inner-shell ionization of atoms. This is a localized process that can be approximated by the scattering of an electron beam from a free atom. We calculate the inelastic differential cross section perturbatively within the framework of quantum electrodynamics (QED). The interaction between the incoming electron and the atom factorizes into a high-energy electron term and the atomic transition current. The matrix elements of the transition current are computed within the relaxed Dirac Hartree Fock method. We analyze the correlation effects arising from the relaxation of the atomic orbitals induced by the creation of a core hole. These effects are particularly relevant in quantum many-body systems and have a significant impact on the shape of the differential cross section near the ionization threshold in EELS spectra. In addition to the continuum, we calculate the discrete excitation spectrum of $\mathrm{DySc}{\mathrm{O}}_3$ using crystal-field multiplet theory. The calculated spectrum shows very good agreement with experimental EELS data.

25 pages, 12 figures

References in corpus (14)

• Multiplet ligand-field theory using Wannier orbitals
• The radiative potential method for calculations of QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atoms
• AMBiT: A program for high-precision relativistic atomic structure calculations
• Atomic many-body effects and Lamb shifts in alkali metals
• QED radiative corrections and many-body effects in atoms: vacuum polarization and binding energy shifts in alkali metals
• Particle-hole configuration interaction and many-body perturbation theory: application to Hg+
• Relaxation effect and radiative corrections in many-electron atoms
• Density Functional Theory versus the Hartree Fock Method: Comparative Assessment
• Bridging nano-optics and condensed matter formalisms in a unified description of inelastic scattering of relativistic electron beams
• The Magic Angle "Mystery" in Electron Energy Loss Spectroscopy: Relativistic and Dielectric Corrections
• Convexity constraints on linear background models for electron energy-loss spectra
• Atomic binding corrections for high energy fixed target experiments
• Relativistic EELS scattering cross-sections for microanalysis based on Dirac solutions
• Data Processing For Atomic Resolution EELS