title: Identification of ice nucleation active sites on feldspar dust particles.
abstract: Mineral dusts originating from Earth's crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts. Here we investigated in closer detail the reasons for its activity and the difference in the activity of the different feldspars. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. K-feldspar showed by far the highest ice nucleation activity. Finally, we give a potential explanation of this effect, finding alkali-metal ions having different hydration shells and thus an influence on the ice nucleation activity of feldspar surfaces.
authors.affiliation: †Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
authors.forename: Tobias
authors.initials: T
authors.lastname: Zolles
authors.affiliation: †Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Burkart
authors.affiliation: †Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Häusler
authors.affiliation: †Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Pummer
authors.affiliation: ‡Faculty of Physics, Aerosol Physics and Environmental Physics, University of Vienna, Boltzmanng. 5, 1090 Vienna, Austria.
authors.forename: Regina
authors.initials: R
authors.lastname: Hitzenberger
authors.affiliation: †Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
authors.forename: Hinrich
authors.initials: H
authors.lastname: Grothe