Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 10: Topical Session Glass Dynamics III

MM 10.2: Vortrag

Montag, 22. März 2010, 15:15–15:30, H16

Structure conserving correlations, inherent structure dynamics, and the Kohlrausch-Williams-Watts behaviour of simulated metallic-glass forming Ni0.5Zr0.5 — •Helmar Teichler — Inst. f. Materialphysik, Univ. Göttingen, 37077 Göttingen, Germany

In glass forming melts near the glass temperature, the alpha-decay reflects relaxation processes with Kohlrausch-Williams-Watts behaviour on macroscopic time scales. Microscopic explanation of these fundamental features is a challenging open question, which needs understanding emergence of extreme slow dynamics with non-exponential response from atomic motions in the melt. Regarding this, we here present an analysis of microseconds-scale molecular dynamics simulation results for glass forming Ni0.5Zr0.5. The concept of "strongly effective particles" (SEPs) is used to relate the properties of macro-scale correlation functions to the atomistic processes in the melt. We show in particular that the Kohlrausch-Williams-Watts behaviour reflects structure conserving correlations (SCC) in the formation and annihilation of SEPs. The SCC make that there are long-time memory-effects in the inherent structure dynamics. Details are discussed concerning the microscopic picture behind the SCC and how to generate for relevant correlators equations of motions that take care of the SCC.