Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 35: Poster Session II

MM 35.11: Poster

Mittwoch, 25. März 2009, 16:30–18:30, P4

Relaxation behavior and rheologie of amorphous solids in the cooperative shear zone-model — •Moritz Schwabe, Dennis Bedorf, and Konrad Samwer — I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany

In the model of the potential energy landscape (PEL) from Stillinger and Weber, it is important to distinguish two different (beta and alpha) relaxations. In the PEL this is described in the change-over to a new local configuration (intrabasin hopping) or to a configuration with a convert potential energy (interbasing hopping). [1] To describe the response of the system in the cooperative shear zone - model to an external stress, a Frenkal-approach is chosen, which shows the decrease of the barrier height in the PEL. [2]

With this background we study the transition from the elastic to the anelastic response of a metallic glass (PdCuSi) via the change of the temperature and the force. To describe this transition from the linear to the nonlinear behavior we will present on the one hand stress-strain curves in the range from ambient temperature to above Tg and on the other hand creep tests with different forces and temperatures. We thank the SFB 602 and the GRK 782 for financial supporting.

[1] John S. Harmon, Marios D. Demetriou, William L. Johnson and Konrad Samwer, Phys. Rev. Lett., 99, p.135502 (2007) [2] William L. Johnson, K. Samwer, Phys. Rev. Lett., 95, p.195501 (2005)