A5072585085- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Planetary Science and Exploration
- Atomic and Molecular Physics
- Magnetic properties of thin films
- Astro and Planetary Science
- Spaceflight effects on biology
- Advanced Condensed Matter Physics
- Radiation Therapy and Dosimetry
- Space Exploration and Technology
- Semiconductor materials and devices
- Ion-surface interactions and analysis
- Diamond and Carbon-based Materials Research
- Effects of Radiation Exposure
- Inorganic Fluorides and Related Compounds
- Perovskite Materials and Applications
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Mass Spectrometry Techniques and Applications
- solar cell performance optimization
- Cultural Heritage Materials Analysis
- Building materials and conservation
- Conservation Techniques and Studies
- Electronic and Structural Properties of Oxides
Royal Belgian Institute for Space Aeronomy
2019-2023
European Research Council
2023
European Commission
2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2021
CEA DAM Île-de-France
2021
UCLouvain
2011-2016
European Theoretical Spectroscopy Facility
2013-2016
École Polytechnique
2014-2016
Centre National de la Recherche Scientifique
2008-2016
Vrije Universiteit Brussel
2013-2014
Thin films of heavily B-doped nanocrystalline diamond (B:NCD) have been investigated by a combination high resolution annular dark field scanning transmission electron microscopy and spatially resolved energy-loss spectroscopy performed on state-of-the-art aberration corrected instrument to determine the B concentration, distribution local environment. Concentrations ~1 3 at.% boron are found be embedded within individual grains. Even though most NCD grains surrounded thin amorphous shell,...
Aberration‐corrected transmission electron microscopy, energy‐loss spectroscopy, and density functional theory (DFT) calculations are used to solve several key questions about the surface structure, particle morphology, distribution nature of nitrogen impurities in detonation nanodiamond (DND) cleaned by a recently developed ozone treatment. All microscopy spectroscopy measurements performed at lowered acceleration voltage (80/120 kV), allowing prolonged detailed experiments be carried out...
The degradation of colors in historical paintings affects our cultural heritage both museums and archeological sites. Despite intensive experimental studies, the origin darkening one most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy high-resolution microscopic x-ray diffraction, we clarify composition damaged paint work demonstrate possible physicochemical processes, induced illumination exposure humidity...
First principles calculations explain the presence, colour, and photo-reactivity of Hg-containing compounds involved in vermilion degradation.
A computational method is presented for angle-resolved photoemission spectra (ARPES) and photoelectron diffraction (PED) in the ultraviolet regime. The one-step model employed both initial valence final continuum states are calculated using finite-cluster, real-space multiple scattering method. Thereby approach versatile provides a natural link to core-level PED. applied Cu(111) band good agreement with experiment found ARPES PED patterns. When patterns integrated over filled of...
Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond functional theory, we describe magnetic ground state Cr-doped TiO2, intensively studied debated dilute oxide. In parallel, correct our LSDA+U (+ superexchange) through GW corrections (GW@LSDA+U) that reproduce position impurity states band gaps in satisfying agreement with experiments. Because different topological coordinations Cr-Cr bonds rutile anatase, induce either ferromagnetic...
Abstract The first human missions on Mars will likely involve several astrobiology‐driven science operations, at sites with high biosignature preservation potential. Here, we present a study of the radiation environment induced by Galactic Cosmic Rays and Solar Energetic Particles Oxia Planum, landing site European Space Agency ExoMars 2022 mission, two different locations in Mawrth Vallis, using Monte Carlo GEometry ANd Tracking 4‐based code dMEREM (detailed Martian Radiation Environment...
In this work an intuitive (TD-DFT) approach was developed to explain the experimental efficiencies seen for organic photovoltaic devices.
We investigate the local polarisability or density using both a conceptual functional theory approach based on linear response function and time-dependent theory. Using zero frequency in latter, we can immediately compare approaches. an analytical expression for kernel, are able to systematically analyse α(r) throughout periodic table. An extension molecules is also made with study of CO molecule retrieving connection between softness polarisability.
The capability of the recently observed dichroic effect in angle-resolved Auger-photoelectron coincidence spectroscopy (DEAR-APECS) to disentangle individual multiplet terms has been exploited study lineshape ${M}_{3}{M}_{45}{M}_{45}$ Auger spectrum measured with $3{p}_{3/2}$ photoelectrons from Cu(111) surface. relevant structure two hole final state is determined an unprecedented sensitivity, including a reliable experimental estimation energy $^{1}D$ term. Spectroscopic data for $3p$...
Knowledge of the electronic stopping curve for swift ions, $S_e(v)$, particularly around Bragg peak, is important understanding radiation damage. Experimentally, however, determination such feature light ions very challenging, especially in disordered systems as liquid water and biological tissue. Recent developments real-time time-dependent density functional theory (rt-TDDFT) have enabled calculation $S_e(v)$ along nm-sized trajectories. However, it still a challenge to obtain meaningful...
Spin selectivity in angle-resolved Auger photoelectron coincidence spectroscopy (AR-APECS) is used to probe electron correlation ferromagnetic thin films. In particular, exploiting the AR-APECS capability discriminate emission events characterized by valence hole pairs created either high or low total spin state, a strong effect Fe M(2,3)VV line shape (measured with 3p photoelectrons) of Fe/Cu(001) films detected and ascribed interactions within majority subband. Such an assignment follows...
Motivated by the radiation damage of solar panels in space, firstly, results Monte Carlo particle transport simulations are presented for proton impact on triple-junction Ga$_{0.5}$In$_{0.5}$P/GaAs/Ge cells, showing projectile penetration cells as a function energy. It is followed systematic {\it ab initio} investigation electronic stopping power protons different layers cell at relevant velocities via real-time time-dependent density functional theory (RT-TDDFT) calculations. The found to...
The Sn ${M}_{5}{N}_{45}{N}_{45}$ Auger spectrum from the $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}\text{\ensuremath{-}}\mathrm{Sn}∕\mathrm{Ge}(111)$ surface has been measured in coincidence with corresponding $3{d}_{5∕2}$ photoelectron. By detecting this pair at appropriate emission angles, contribution spin-symmetric (triplet) and spin-antisymmetric (singlet) final states can be selectively enhanced or suppressed. This dichroic effect...
Auger-photoelectron coincidence spectroscopy is used for investigating the electronic properties of a CoO thin film above and below magnetic transition temperature (TN). By using dichroic effect in angle-resolved measurements, we identify assign well-defined high-spin low-spin structures spite otherwise featureless Auger singles spectra, typically found open-band systems. The disappearance dichroism temperatures just TN indicates collapse surface short-range order, presumably due to strongly...
Modelling the inelastic scattering of electrons in water is fundamental, given their crucial role biological damage. In Monte Carlo track-structure (MC-TS) codes used to assess damage, energy loss function (ELF), from which cross sections are extracted, derived different semi-empirical optical models. Only recently have first ab initio results for ELF and become available. For benchmarking purpose, this work, we present linear-response time-dependent density functional theory calculations...
The photophysics of interstellar ices and condensed molecules adsorbed on grains is primary importance for studies the origin specific handedness complex organic delivered to early Earth homochirality building blocks life. Here, we present quantum mechanical calculations based time-dependent density functional theory absorption circular dichroism (CD) isovaline its chiral precursor 5-ethyl-5-methylhydantoin, both observed in meteoritic findings. systems are considered their geometrical...
In this paper we present a single-particle scattering approach for the angular correlation between photoelectron and subsequent Auger electron from atomic targets. This method is proposed as an alternative with respect to usual density matrix formalism, since it more convenient extension solid state case. Such required by great progress made in field of coincidence spectroscopy condensed matter systems. We derived tensor expression cross section equivalent terms functions has been treated...