Theoretical modelling of steps and surface oxidation on CaF2(111)

Atomic geometry of steps on metal-oxide single crystals

“…For any ionic material, there will almost certainly be relaxation along step edges; the charges on step-edge ions may also be slightly different than those on terraces or in the bulk [16][17][18]. However, for complex oxides neither the relaxation nor charge transfer are known.…”

Effect of surface orientation on dissolution rates and topography of CaF2

“…To date, the effect of dissolution on the surface has not been experimentally studied for other surface orientations of the fluorite structure. However, theoretical studies derived different surface energies according to their surface chemistry for different surface orientations and predicted the development of stepped surfaces as a way of minimizing surface energy (Tasker, 1980;Puchina et al, 1998;Puchin et al, 2001).…”

Structure and diffusion of intrinsic defects, adsorbed hydrogen, and water molecules at the surface of alkali-earth fluorides calculated using density functional theory

“…2 For alkali-earth surfaces, their interaction with water is particularly relevant due to their historical role in acid production 3,4 and their developing role as dielectric thin films in micro-and optoelectronics. 5,6 The basic fluorite bulk and surface structures have been the subject of numerous experimental and computational studies, [7][8][9][10][11][12][13][14][15][16][17][18][19] and more recent low-energy electron diffraction studies have looked into the surface's structure in detail. 20 Studies of water on the surface have been more sparse, generally predicting that water weakly interacts with the surface in normal conditions, 21 but can dissociate or even etch the surface in the presence of surface defects or at high pH.…”