Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 31: Oxide and Insulator Surfaces: Structure, Epitaxy and Growth I

O 31.2: Vortrag

Dienstag, 21. März 2017, 10:45–11:00, WIL C107

Ultra-thin films of iron-silicate — •Gina Peschel¹, Alexander Fuhrich¹, Hagen W. Klemm¹, Mauricio Prieto¹, Dietrich Menzel^1,2, 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.