Dresden 2014 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 56: Liquid and Amorphous Metals IV

MM 56.1: Vortrag

Donnerstag, 3. April 2014, 11:30–11:45, IFW A

Scenarios of structure stabilization in amorphous AlMnCu — •Syed Sajid Ali Gillani and Peter Häussler — Chemnitz University of Technology, Institute of Physis, 09107 Chemnitz, Germany

Structural studies of binary amorphous AlMn and AlCu and two different cuts through the ternary AlMnCu show purely amorphous regions, those with additional quasi-crystalline features, as well as those with nano-crystalline inclusions. Our analysis focuses on global resonance effects between two global subsystems, the Fermi gas as one and the static structure as the other one. The global resonances in this case are self-organizing via the exchange of a characteristic momentum, supported by density anomalies, hybridization effects and phase separations. For both, the binary a-AlMn as well as the binary a-AlCu systems, the corresponding structure factors S(K) show the resonance peaks at K_pe = 2k_F. They correspond in r-space to a spherical-periodic atomic order. The self-organizing processes are limited since e.g. hybridization needs minimal as well as maximal contents of transition metals (here Mn) and changes if we replace the Mn. To go more into details, we go along two cuts through the ternary AlMnCu and so are able to cross the several limits at different compositions. Amorphous AlMnCu seems to be a model system for a deeper understanding of those effects. For one cut we start at a-Al₅₀Mn₅₀ and add Cu. A second cut starts from a-Al₆₀Cu₄₀, keeps the Cu-content constant and varies both, the Al- as well as the Mn-content. We report on the results.