Structural relaxation as seen by quasielastic neutron scattering on viscous Zr-Ti-Cu-Ni-Be droplets

Journal article


Publication Details

Author(s): Yang F, Kordel T, Holland-Moritz D, Unruh T, Meyer A
Journal: Journal of Physics: Condensed Matter
Publisher: IOP PUBLISHING LTD
Publication year: 2011
Volume: 23
Journal issue: 25
ISSN: 0953-8984
eISSN: 1361-648X


Abstract


In bulk glass forming Zr46.8Ti8.2Cu7.5Ni10Be27.5 (Vit4) the mean Ni, Ti, and Cu self-diffusion coefficient at the liquidus is about 10(-10) m(2) s(-1). Compared with these values, diffusion coefficients derived from various reported viscosity data by rescaling them via the Stokes-Einstein relation exhibit different temperature dependence and absolute values are a factor of 5-10 smaller. This raises the question of whether a slow Zr subsystem exists in the melt at temperatures well above the liquidus temperature. Here, we address this question by studying microscopic dynamics employing quasielastic neutron scattering. We utilized containerless sample processing in a novel electrostatic levitation apparatus. This excludes reactions between samples and crucible materials and gives access to a wide momentum transfer range of about 0.2-2.6 angstrom(-1). We studied the dynamics governed by the Ni, Ti, and Cu diffusive motion as well as by collective Zr motion. At 1255 K, both correlation functions decay to zero on a timescale of about 20 ps. This shows that there is neither a decoupling between the atomic dynamics of the various components nor a slow Zr subsystem in the equilibrium melt.



FAU Authors / FAU Editors

Unruh, Tobias Prof. Dr.
Professur für Nanomaterialcharakterisierung (Streumethoden)


External institutions with authors

Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)


How to cite

APA:
Yang, F., Kordel, T., Holland-Moritz, D., Unruh, T., & Meyer, A. (2011). Structural relaxation as seen by quasielastic neutron scattering on viscous Zr-Ti-Cu-Ni-Be droplets. Journal of Physics: Condensed Matter, 23(25). https://dx.doi.org/10.1088/0953-8984/23/25/254207

MLA:
Yang, Fan, et al. "Structural relaxation as seen by quasielastic neutron scattering on viscous Zr-Ti-Cu-Ni-Be droplets." Journal of Physics: Condensed Matter 23.25 (2011).

BibTeX: 

Last updated on 2018-06-08 at 20:23