Photoelectron and electron microscopy investigation of laboratory grown Mg-silicate space dust analogues
Abstract
The atomic structure at the surface of interstellar silicate dust particles likely plays a key role in a variety of chemical processes occurring in star- and planet-forming regions of the interstellar medium (ISM). Here, we use the photoelectric effect to characterize, in situ, the local chemical structure of Mg-silicate nanoparticulate films, and ex situ electron microscopy to trace changes to morphology resulting from different starting compositions. Nanoparticulate films are prepared via co-deposition of Si, Mg and O atoms on a graphitic substrate under ultra-high vacuum (UHV) and are characterised with X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Analysis, supported by density functional theory calculations, shows that adjusting the Mg-to-Si ratio from 3.5 to 1.8 changes particle composition from a mixture of MgO and Mg-silicate towards predominantly Mg-silicate. Annealing in UHV also pushes the composition towards Mg-silicate, however, non-stoichiometric chemical motifs are always observed, presenting a distribution of potentially catalytically active sites. Electron microscopy images show composition-dependent film morphologies that restructure differently upon thermal annealing. The Mg-silicate nanoparticulate films presented here are characterised as a 2D version of ISM analogue dust particles prepared via laser ablation and are therefore a more readily suitable model for surface science investigations into the catalytic properties of interstellar Mg-silicate dust.
Related
- Laboratory Measurements of Energy Partitioning and Anomalous Electron Heating in Magnetized, Perpendicular Collisionless Shocks
- Kinematic analysis of the TNG50 Milky Way and Andromeda analogues
- A systematic assessment of the short-term X-ray behaviour of the γ Cas analogues
- Dust in cold and warm dark matter in a suite of zoom-in simulations of Milky Way analogues
- Environmental Dependence of Satellite Planarity and Orbital-Pole Coherence around Milky Way Analogues in a Hydrodynamical Cosmological Simulation
BibTeX
@misc{holleufer2026photoelectron,
title = {{Photoelectron and electron microscopy investigation of laboratory grown Mg-silicate space dust analogues}},
author = {Steffen Friis Holleufer and Mie Andersen and Frederik Granzow Doktor and Lars Eric Borchert and Martin Wibrand Larsen and Duncan S. Sutherland and Zheshen Li and Alexei Preobrajenski and Jeppe Vang Lauritsen and Cornelia Jäger and Liv Hornekær and Andrew Cassidy},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35925},
eprint = {2609.35925},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35925},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Photoelectron and electron microscopy investigation of laboratory grown Mg-silicate space dust analogues
AU - Steffen Friis Holleufer
AU - Mie Andersen
AU - Frederik Granzow Doktor
AU - Lars Eric Borchert
AU - Martin Wibrand Larsen
AU - Duncan S. Sutherland
AU - Zheshen Li
AU - Alexei Preobrajenski
AU - Jeppe Vang Lauritsen
AU - Cornelia Jäger
AU - Liv Hornekær
AU - Andrew Cassidy
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.35925
UR - https://arxiv.org/abs/2609.35925
AB - The atomic structure at the surface of interstellar silicate dust particles likely plays a key role in a variety of chemical processes occurring in star- and planet-forming regions of the interstellar medium (ISM). Here, we use the photoelectric effect to characterize, in situ, the local chemical structure of Mg-silicate nanoparticulate films, and ex situ electron microscopy to trace changes to morphology resulting from different starting compositions. Nanoparticulate films are prepared via co-deposition of Si, Mg and O atoms on a graphitic substrate under ultra-high vacuum (UHV) and are characterised with X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Analysis, supported by density functional theory calculations, shows that adjusting the Mg-to-Si ratio from 3.5 to 1.8 changes particle composition from a mixture of MgO and Mg-silicate towards predominantly Mg-silicate. Annealing in UHV also pushes the composition towards Mg-silicate, however, non-stoichiometric chemical motifs are always observed, presenting a distribution of potentially catalytically active sites. Electron microscopy images show composition-dependent film morphologies that restructure differently upon thermal annealing. The Mg-silicate nanoparticulate films presented here are characterised as a 2D version of ISM analogue dust particles prepared via laser ablation and are therefore a more readily suitable model for surface science investigations into the catalytic properties of interstellar Mg-silicate dust.
ER -