Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 27: Transport I - Materials/Methods

MM 27.2: Talk

Tuesday, April 1, 2014, 12:00–12:15, IFW B

Diffusion of Atoms and Vacancies in Thin Nano Crystalline Platinum Films — •Wolfgang Gruber¹, Johanna Rahn¹, Florian Strauss¹, Lars Dörrer¹, Erwin Hüger¹, Michael Horisberger², Thomas Geue², Jochen Stahn², Carsten Bähtz³, Wolfram Leitenberger⁴, and Harald Schmidt¹ — ¹TU Clausthal — ²Paul Scherrer Institut — ³Helmholtz-Zentrum Dresden-Rossendorf — ⁴Universität Potsdam

An important characteristic of thin metal films deposited on substrates is the presence of a high number of defects in the metal film which is correlated to residual stress and strain. During heat treatment strain in the metal films relaxes. The relative changes of the film thickness and the interplanar distance are correlated to the change of the defect concentration during relaxation. In-situ X-ray diffraction and X-ray reflectometry using synchrotron radiation revealed that strain relaxation is accompanied by an increase of the vacancy concentration at the surface of the film [1]. In this work we present experimental results supporting the stress relaxation model outlined in [1]. To clarify the rate determining process for strain relaxation, grain boundary and volume self-diffusion of platinum is investigated. Samples enriched in the stable isotope 194Pt as tracer source were prepared and used for analysis with secondary ion mass spectrometry and neutron reflectometry. [1] W. Gruber, S. Chakravarty, C. Baehtz, W. Leitenberger, M. Bruns, A. Kobler, C. Kübel, H. Schmidt, Phys. Rev. Lett. 117 (2011) 265501.