Regensburg 2010 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 18: Topical Session Glass Dynamics V

MM 18.1: Topical Talk

Tuesday, March 23, 2010, 10:15–10:45, H16

The low-frequency vibrational properties of model bulk metallic glasses within the harmonic approximation. — •Peter Derlet¹, Robert Maass², and Jörg Löffler² — ¹Condensed Matter Theory Group, Paul Scherrer Institut, Switzerland — ²Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, Switzerland

Bulk Metallic Glasses (BMGs) exhibit a rich variety of vibrational properties resulting from the significant topological disorder which occurs at the atomic scale. In the low-frequency regime confined resonant vibrational modes occur that manifest themselves as a Bose peak in the vibrational density of states. However, the precise nature of these modes and how they are influenced by local atomic structure remains unclear. Using standard harmonic analysis, this study investigates various aspects of the problem by diagonalising the Hessian of atomistic BMG structures derived from molecular dynamics simulations via a binary Lennard Jones pair potential. The results are discussed in terms of their possible relation to atomic transition pathways that result in local shear deformation zones - the underlying microscopic process contributing to the plasticity of BMGs.