Aarhus University Seal / Aarhus Universitets segl

Formation of water ice clusters on graphite

Research output: Contribution to conferencePosterResearch

Standard

Formation of water ice clusters on graphite. / Simonsen, Frederik Doktor Skødt; Kyrkjebø, Signe; Balog, Richard et al.

2021.

Research output: Contribution to conferencePosterResearch

Harvard

APA

CBE

MLA

Vancouver

Author

Bibtex

@conference{1c45a327b29f428da0583c4e4c947cc1,
title = "Formation of water ice clusters on graphite",
abstract = "The process of surface wetting and formation of ice structures on surfaces havebeen studied extensively. Beyond being of great importance within the eld ofsurface technologies [1], it may also govern freeze-out mechanisms in the inter-stellar medium (ISM) [2]. In cold regions of the ISM icy mantles exist on thesurface of interstellar dust grains. These may act as a heterogeneous catalysissystem where adsorbed molecules may interact, sometimes mediated by photonirradiation, to form large and complex molecules [3]. Structural dierences ofwater ice, which are detectable in IR-spectroscopy [4], will have an impact onthe interaction between complex molecules in the ice, e.g. for adsorption anddiusion characteristics [5]. The structure of the water ice mantle depends onthe thermal history and will dier depending on formation conditions.Here we examine water ice formation on highly oriented pyrolytic graphite(HOPG) in the sub-monolayer regime using a low-temperature scanning tun-nelling microscope (LT-STM) functioning at 5 K. Sub-monolayer amounts ofheavy water (D2O) were deposited onto an HOPG surface kept at 40 K. Pre-sented in Figure 1 is water ice clusters grown at 40 K via molecular depositionon the HOPG surface. A clear diusion limited aggregation (DLA [6]) growthis visible from the fractal structure of the clusters, both near step edges and forindividual nucleation sites. Only 2D growth is observed at these sub-monolayercoverages. DLA leads to low densities and an amorphous and porous structurewhich with growth may form the reputed amorphous solid water of icy grainmantles. Finally, we investigate how an oxygen functionalised O-HOPG surfacemay inuence the already complex growth of water ice clusters on interstellargrain analogues, oering a unique look into non heat-treated water ice clusters.",
author = "Simonsen, {Frederik Doktor Sk{\o}dt} and Signe Kyrkjeb{\o} and Richard Balog and Liv Hornek{\ae}r and Prashant Srivastava and Karina Morgenstern",
year = "2021",
language = "English",

}

RIS

TY - CONF

T1 - Formation of water ice clusters on graphite

AU - Simonsen, Frederik Doktor Skødt

AU - Kyrkjebø, Signe

AU - Balog, Richard

AU - Hornekær, Liv

AU - Srivastava, Prashant

AU - Morgenstern, Karina

PY - 2021

Y1 - 2021

N2 - The process of surface wetting and formation of ice structures on surfaces havebeen studied extensively. Beyond being of great importance within the eld ofsurface technologies [1], it may also govern freeze-out mechanisms in the inter-stellar medium (ISM) [2]. In cold regions of the ISM icy mantles exist on thesurface of interstellar dust grains. These may act as a heterogeneous catalysissystem where adsorbed molecules may interact, sometimes mediated by photonirradiation, to form large and complex molecules [3]. Structural dierences ofwater ice, which are detectable in IR-spectroscopy [4], will have an impact onthe interaction between complex molecules in the ice, e.g. for adsorption anddiusion characteristics [5]. The structure of the water ice mantle depends onthe thermal history and will dier depending on formation conditions.Here we examine water ice formation on highly oriented pyrolytic graphite(HOPG) in the sub-monolayer regime using a low-temperature scanning tun-nelling microscope (LT-STM) functioning at 5 K. Sub-monolayer amounts ofheavy water (D2O) were deposited onto an HOPG surface kept at 40 K. Pre-sented in Figure 1 is water ice clusters grown at 40 K via molecular depositionon the HOPG surface. A clear diusion limited aggregation (DLA [6]) growthis visible from the fractal structure of the clusters, both near step edges and forindividual nucleation sites. Only 2D growth is observed at these sub-monolayercoverages. DLA leads to low densities and an amorphous and porous structurewhich with growth may form the reputed amorphous solid water of icy grainmantles. Finally, we investigate how an oxygen functionalised O-HOPG surfacemay inuence the already complex growth of water ice clusters on interstellargrain analogues, oering a unique look into non heat-treated water ice clusters.

AB - The process of surface wetting and formation of ice structures on surfaces havebeen studied extensively. Beyond being of great importance within the eld ofsurface technologies [1], it may also govern freeze-out mechanisms in the inter-stellar medium (ISM) [2]. In cold regions of the ISM icy mantles exist on thesurface of interstellar dust grains. These may act as a heterogeneous catalysissystem where adsorbed molecules may interact, sometimes mediated by photonirradiation, to form large and complex molecules [3]. Structural dierences ofwater ice, which are detectable in IR-spectroscopy [4], will have an impact onthe interaction between complex molecules in the ice, e.g. for adsorption anddiusion characteristics [5]. The structure of the water ice mantle depends onthe thermal history and will dier depending on formation conditions.Here we examine water ice formation on highly oriented pyrolytic graphite(HOPG) in the sub-monolayer regime using a low-temperature scanning tun-nelling microscope (LT-STM) functioning at 5 K. Sub-monolayer amounts ofheavy water (D2O) were deposited onto an HOPG surface kept at 40 K. Pre-sented in Figure 1 is water ice clusters grown at 40 K via molecular depositionon the HOPG surface. A clear diusion limited aggregation (DLA [6]) growthis visible from the fractal structure of the clusters, both near step edges and forindividual nucleation sites. Only 2D growth is observed at these sub-monolayercoverages. DLA leads to low densities and an amorphous and porous structurewhich with growth may form the reputed amorphous solid water of icy grainmantles. Finally, we investigate how an oxygen functionalised O-HOPG surfacemay inuence the already complex growth of water ice clusters on interstellargrain analogues, oering a unique look into non heat-treated water ice clusters.

M3 - Poster

ER -