Dresden 2009 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 42: Nanostructured Materials III
MM 42.6: Talk
Thursday, March 26, 2009, 15:15–15:30, IFW A
Delocalization mechanisms of excess free-volume in nanoglasses — •Daniel Sopu1, Karsten Albe1, Yvonne Ritter1, and Herbert Gleiter2 — 1Institut für Materialwissenschaft, TU Darmstadt, Petersenstr. 23, D-64287 Darmstadt, Germany — 2Institute of Nanotechnology, Karlsruhe Institute of Technology, P.O. Box 3640, D-76021 Karlsruhe, Germany
Molecular dynamics simulations are presented which provide a detailed picture of the structure of nanoglasses, a class of material which can be synthesized by consolidating nanometer-sized glassy particles. Our results provide evidence the existence of glass-glass interfaces between the consolidated particles. These interfaces are characterized by an excess free volume. By comparing simulations for covalently bonded Ge nanoglass and metallic CuZr nanoglass, we find that the delocalization of this free volume is driven by homogeneous plastic flow and by thermally activated diffusion. These results suggest that the overall density, microstructure and atomic structure of nanoglasses can be adjusted by the initial particle size and chemical composition as well as by the annealing conditions.