A5020734479- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Force Microscopy Techniques and Applications
- Electronic and Structural Properties of Oxides
- Magnetic properties of thin films
- Semiconductor materials and devices
- Spectroscopy and Quantum Chemical Studies
- Surface and Thin Film Phenomena
- Quantum, superfluid, helium dynamics
- Acoustic Wave Resonator Technologies
- Advanced Materials Characterization Techniques
- Quantum and electron transport phenomena
- Quantum Dots Synthesis And Properties
- Machine Learning in Materials Science
- High-pressure geophysics and materials
- Mechanical and Optical Resonators
- Physics of Superconductivity and Magnetism
- Thermal properties of materials
- Advanced Thermoelectric Materials and Devices
- Topological Materials and Phenomena
- Terahertz technology and applications
- Advanced Physical and Chemical Molecular Interactions
- Advanced Chemical Physics Studies
- Near-Field Optical Microscopy
- Thermal Expansion and Ionic Conductivity
Uppsala University
2016-2025
We introduce a novel method for the simulation of impact scattering in vibrational scanning transmission electron microscopy energy loss spectroscopy simulations. The phonon-loss process is modeled by combination molecular dynamics and elastic multislice calculations within modified frozen phonon approximation. key idea thereby to use so-called $\ensuremath{\delta}$ thermostat classical generate frequency dependent configurations vibrating specimen's atomic structure. includes correlated...
We present a method for computing angle-resolved electron energy loss and gain spectroscopies phonon magnon excitations in transmission microscopy. Fractional scattering intensities are derived from the temperature-dependent time autocorrelation of auxiliary beam wave function. This captures both single multiple processes, as well dynamical diffraction effects, while remaining computationally efficient easy to parallelize. Published by American Physical Society 2025
We propose a simple approach to simulating the phonon sector in electron energy-loss spectroscopy (EELS), as implemented scanning transmission microscopy. Simplification of problem is obtained by working with density states (PDOS), function energy, which an integral over details dispersion relations due correlated motions atoms. For given PDOS, we derive spectral distribution function, distribute total inelastic scattering, calculated within quantum excitation phonons model, into...
Phonon dispersion relations are widely used to elucidate the vibrational properties of materials. As an emerging technique, momentum-resolved spectroscopy in scanning transmission electron microscopy offers unparalleled approach explore q-dependent phonon behavior at local structures. In this study, we systematically investigate monolayer graphene across several Brillouin zones (BZs) using and find that optical signals vanish Γ points with indices (hk0) satisfying h+2k=3n (n denoted...
Abstract The decreasing size of modern functional magnetic materials and devices cause a steadily increasing demand for high resolution quantitative characterization. Transmission electron microscopy (TEM) based measurements the energy-loss chiral dichroism (EMCD) may serve as needed experimental tool. To this end, we present reliable robust electron-optical setup that generates controls user-selectable single state vortex beams with defined orbital angular momenta. Our set-up is on standard...
We compare the frequency-resolved frozen phonon multislice (FRFPMS) method [introduced in P. M. Zeiger and J. Rusz, Phys. Rev. Lett. 124, 025501 (2020)] with other theoretical approaches used to account for inelastic scattering of high-energy electrons, namely, first-order Born approximation quantum excitation phonons model. show that these theories lead similar expressions single inelastically scattered intensity as a function momentum transfer an anisotropic harmonic oscillator weak phase...
We explore the capabilities of frequency-resolved frozen phonon multislice method introduced in [Phys. Rev. Lett. 124, 025501 (2020)] to model inelastic vibrational scattering transmission electron microscopy. review detail and discuss advantages using a so-called hotspot thermostat instead $\ensuremath{\delta}$ used our first report. apply simulate energy loss spectra hexagonal boron nitride under plane wave illumination. Simulated spectroscopic information well represents theoretical band...
This study delves deeply into the complexities of magnon diffuse scattering (MDS) in bcc Fe, unraveling interplay between atomic vibrations and signals scanning transmission electron microscopy (STEM). The work details role temperature to explore feasible paths for MDS detection that could bring new understanding magnetic solid-state phenomena at nanometer scale.
We present a theory and simulation of diffuse scattering due to the excitation magnons in scanning transmission electron microscopy. The calculations indicate that can atomic contrast when detected by energy-loss spectroscopy using atomic-size beams. results presented here intensity magnon bcc iron at 300 K is 4 orders magnitude weaker than thermal arising from vibrations.
Recent developments in experiments with vibrational electron energy loss spectroscopy (EELS) have revealed spectral shape variations at spatial resolutions down to sub-atomic scale. Interpretation terms of local phonon density states enables their qualitative understanding, yet a more detailed analysis is calling for advances theoretical methods. In Zeiger and Rusz, Phys. Rev. Lett. 124, 025501 (2020) we presented frequency resolved frozen multislice method simulations EELS. Detailed plane...
Dopants, even single atoms, can influence the electrical and magnetic properties of materials. Here we demonstrate opportunity for detecting response an embedded impurity in a nonmagnetic host material. We combine depth sectioning approach with electron circular dichroism scanning transmission microscopy to compute depth-resolved inelastic-scattering cross section Co buried crystal GaAs. Our calculations suggest that dichroic signal intensity is sensitive lateral position probe relative...
We have simulated the magnetic Bragg scattering in transmission electron microscopy two antiferromagnetic compounds, NiO and LaMnAsO. This weak phenomenon was experimentally observed by Loudon (2012). computationally reproduced Loudon's experimental data, for comparison we performed calculations LaMnAsO compound as a more challenging case, containing lower concentration of elements strongly heavier non-magnetic elements. also described thickness voltage dependence intensity spot both...
We explore the inelastic electron scattering in SrTiO3, PbTiO3, and SiC their phonon energy range, challenging assumption that polaritons are excluded at large angles high-resolution transmission energy-loss spectroscopy. demonstrate through multiple scattering, beam can excite both phonons polaritons, relative proportion of each varies depending on structure factor angle. Integrating dielectric theory, density functional multi-slice simulations, we provide a comprehensive framework for...
Phonon dispersion is widely used to elucidate the vibrational properties of materials. As an emerging technique, momentum-resolved spectroscopy in scanning transmission electron microscopy (STEM) offers unparalleled approach explore q-dependent phonon behavior at local structures. In this study, we systematically investigate monolayer graphene across several Brillouin zones (BZs) using and find that optical signals vanish {\Gamma} points with indices (hk0) satisfying h+2k=3n (n denoted...