title: Can Ice-Like Structures Form on Non-Ice-Like Substrates? The Example of the K-feldspar Microcline.
abstract: Feldspar minerals are the most common rock formers in Earth's crust. As such they play an important role in subjects ranging from geology to climate science. An atomistic understanding of the feldspar structure and its interaction with water is therefore desirable, not least because feldspar has been shown to dominate ice nucleation by mineral dusts in Earth's atmosphere. The complexity of the ice/feldspar interface arising from the numerous chemical motifs expressed on the surface makes it a challenging system. Here we report a comprehensive study of this challenging system withab initiodensity functional theory calculations. We show that the distribution of Al atoms, which is crucial for the dissolution kinetics of tectosilicate minerals, differs significantly between the bulk environment and on the surface. Furthermore, we demonstrate that water does not form ice-like overlayers in the contact layer on the most easily cleaved (001) surface of K-feldspar. We do, however, identify contact layer structures of water that induce ice-like ordering in the second overlayer. This suggests that even substrates without an apparent match with the ice structure may still act as excellent ice nucleating agents.
authors.affiliation: Thomas Young Centre and Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom; London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom.
authors.forename: Philipp
authors.initials: P
authors.lastname: Pedevilla
authors.affiliation: Thomas Young Centre and Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom; London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cox
authors.affiliation: Thomas Young Centre and Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, United Kingdom.
authors.forename: Ben
authors.initials: B
authors.lastname: Slater
authors.affiliation: Thomas Young Centre and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom; London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, United Kingdom.
authors.forename: Angelos
authors.initials: A
authors.lastname: Michaelides