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O: Fachverband Oberflächenphysik
O 31: Oxide and Insulator Surfaces: Structure, Epitaxy and Growth I
O 31.2: Talk
Tuesday, March 21, 2017, 10:45–11:00, WIL C107
Ultra-thin films of iron-silicate — •Gina Peschel1, Alexander Fuhrich1, Hagen W. Klemm1, Mauricio Prieto1, Dietrich Menzel1,2, Thomas Schmidt1, and Hans-Joachim Freund1 — 1Department of Chemical Physics, Fritz-Haber-Institute of the Max-Planck Society, Berlin, Germany — 2Physik-Department E20, Technische Universität München, Garching, Germany
Silicates belong to the most widely existing minerals in nature and are thus extensively used in our society. Consisting only of Si and O the system is known as silica. However, some silicon atoms can be substituted by iron in order to prepare a model system for zeolite structures, known for their very high catalytic properties. Preparing ultra-thin films offers the possibility to understand the correlation between structure and reactivity and functionalize these materials even more. This study addresses the growth and structure of ultra-thin iron-silicate films on Ru(0001) using the methods of LEEM, LEED, XPS and XPEEM.
Our studies reveal that on Ru(0001) the formation of iron-silicate is energetically favoured compared to a phase separation of pure iron-oxide and silica domains. XPS results fit well to a model with a silica layer bound to a layer of FeO on top of the Ru(0001) support. Silica orders in form of a (√3 x √3) R30∘ regarding the FeO layer, as could be seen in the LEED pattern. Thus silica is well ordered on top of FeO and arranged regarding the Fe atoms.