Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Poster session

MM 23.10: Poster

Dienstag, 26. Februar 2008, 14:45–18:00, Poster B

Critical Packing Fraction in Multicomponent, Glass Forming Metallic Liquids — •Suresh M. Chathoth, Bernd Damaschke, and Konrad Samwer — I. Physikalisches Institut,Friedrich-Hund-Platz 1,37077 Goettingen,Germany

Glass forming Ni59.5Nb40.5 and Ni60Nb34.8Sn5.2 have been investigated in their equilibrium liquid by quasielastic neutron scattering. These liquids exhibit extraordinary high packing fraction[1]. Structural relaxation shows stretching in time and extent of stretching depends on the temperature of the liquid. The self-diffusivity decreases about two orders of magnitude within 360 K. From the beta-relaxation, tau-scaling analysis of self-diffusion and mean relaxation times of the alpha-process the critical packing fraction of these liquids have been derived. Our results provide, for the first time, an experimentally observed value for the critical packing fraction in the glass forming metallic liquids and is in good agreement with mode-coupling theory prediction[2].

We gratefully acknowledge the financial support from SFB 602 TP B8 and DLR under grant No. 50WM0541.

1.S. Mukherjee, Z. Zhou, W. L. Johnson, and W. K. Rhim, J. Non-Cryst. Solid 337, 21 (2004).

2.W. Götze, J. Phys: Condens. Matter 2, 8485 (1990).