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DS: Fachverband Dünne Schichten
DS 45: Thin Film Properties: Structure, Morphology and Composition III
DS 45.4: Vortrag
Freitag, 20. März 2020, 10:15–10:30, CHE 89
Investigation of early stage kinetics of SBS glasses in aqueous solutions using a slow positron beam — •Eric Hirschmann1,3, Maik Butterling1, Oskar Liedke1, Ahmed Gamal Attallah1, Andreas Wagner1, Dirk Enke2, and Reinhard Krause-Rehberg3 — 1Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — 2Universität Leipzig, Leipzig, Germany — 3Martin-Luther-Universität Halle-Wittenberg, Halle(Saale), Germany
Thin porous layers at the surface of sodium borosilicate glass(200-2000 nm) were generated via a combination of phase separation and selective leaching. It is possible to control the range of pore size by modifying the heat treatment and the layer thickness by varying the leaching process. The kinetic reaction of the leeching process in SBS is currently described by Sirenek et al. Unfortunately, all approximations base on experiments with high acid concentrations and long leeching periods. Furthermore, due to the thickness and roughness of the thin porous layer it becomes hard to analyse the layer with standard methods like SEM or liquid nitrogen adsorption. In thin porous layers the amount of material becomes so small that most conventional techniques fail caused by a leak of accessibility. Also, an imaging procedure like SEM is difficult due to the isolating properties of glass. Therefore, we used the mono energetic positron source (MePS) at HZDR in Dresden to characterize the layer thickness and pore size simultaneously. As a result we could calculate the layer thickness for different samples using Makhovian profiles and additionally the pore size as well as the pore size distribution based on the extended Tao-Eldrup model.