Dresden 2011 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 42: Poster I: Progress in Micro- and Nanopatterning: Techniques and Applications (jointly with O); Spins in Organic Materials; Ion Interactions with Nano Scale Materials; Organic Electronics and Photovoltaics; Plasmonics and Nanophotonics (jointly with HL and O); High-k and Low-k Dielectrics (jointly with DF); Organic Thin Films; Nanoengineered Thin Films; Layer Deposition Processes; Layer Properties: Electrical, Optical, and Mechanical Properties; Thin Film Characterisation: Structure Analysis and Composition; Application of Thin Films

DS 42.75: Poster

Mittwoch, 16. März 2011, 15:00–17:30, P1

Mechanical dissipation in thermally grown silica at low temperatures — •Julius Komma¹, Christian Schwarz¹, Gerd Hofmann¹, Daniel Heinert¹, Ronny Nawrodt¹, Giles Hammond², and Paul Seidel¹ — ¹Friedrich-Schiller-Universität Jena, Institut für Festkörperphysik, Helmholtzweg 5, D-07743 Jena, Germany — ²Glasgow University, G12 8QQ Glasgow, UK

Silica (SiO₂) is a common material as low index material in thin optical layers. Its mechanical loss is of great interest since the thermal noise of a surface layer is directly related to its mechanical loss by means of the fluctuation dissipation theorem. It is well known that bulk silica shows a very large dissipation peak at cryogenic temperatures between 30 and 40 K.

We present a detailed analysis of the mechanical loss of thin silica layers with a thickness between 0.1 and 3 µ m in a temperature range from 5 to 300 K. The measurements have been performed in a ring-down technique. The layers have been produced by thermal oxidation of thin silicon flexures.

The dependence of the mechanical loss of the layer thickness is discussed and a possible transition of the micro-structure from a thin layer to a thick layer model is presented. The comparison of the activation energy of the dissipation process reveals differences between the bulk silica and thin layer silica samples.

This work is supported by the German Science Foundation (DFG) within the SFB Transregio 7.