Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 38: Liquid and Amorphous Metals

MM 38.7: Vortrag

Mittwoch, 28. März 2012, 16:30–16:45, H 1029

Fraction of un-displaced atoms, structure conserving correlations, and temporal decay of structure fluctuations in simulated Ni0.5Zr0.5 melt — •Helmar Teichler — Inst. f. Materialphysik, Univ. Göttingen, Göttingen, Germany

The highly elaborated mode coupling theory provides a powerful tool to describe the temporal decay of fluctuations in melts. Notwithstanding this, there remains the question for the atomistic process behind the decay. To approach this problem, we analyzed simulation data of a Ni0.5Zr0.5 model close to its glass temperature at the accessible cooling rates. Recurring to our recent approach (H. Teichler, PRL, 107,067801 (2011)) we used as main tool the time evolution of the fraction of un-displaced particles (FUDP). The analysis shows that the alpha decay reflects the ultimate decrease of the FUDP. It irrefutably proves that the structural decay is due to temporal accumulation of incoherent short-ranged displacement events, where the stretched exponential behavior reflects structure conserving correlation in the accumulation process. In the contribution we present, in particular, a concise iteration procedure that describes the fluctuation decay over about eight decades from atomic vibrations to the beta and the alpha region.