Hostname: page-component-7b7567c8c-tnzcf Total loading time: 0 Render date: 2026-11-14T04:59:01.554Z Has data issue: false hasContentIssue false

Diffusion in Metallic Glasses and Supercooled Melts

Published online by Cambridge University Press:  17 March 2011

F. Faupel
Affiliation:
Lehrstuhl für Materialverbunde, Technische Fakultät der Universität Kiel, Kaiserstr. 2, D-24143 Kiel, Germany, ff@tf.uni-kiel.de
K. Rätzke
Affiliation:
Lehrstuhl für Materialverbunde, Technische Fakultät der Universität Kiel, Kaiserstr. 2, D-24143 Kiel, Germany, ff@tf.uni-kiel.de
H. Ehmler
Affiliation:
Now at: MPI für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching, Germany
P. Klugkist
Affiliation:
Now at:MPI für Metallforschung, Seestr. 92, D-70174 Stuttgart, Germany
V. Zöllmer
Affiliation:
Lehrstuhl für Materialverbunde, Technische Fakultät der Universität Kiel, Kaiserstr. 2, D-24143 Kiel, Germany, ff@tf.uni-kiel.de
C. Nagel
Affiliation:
Now at: Fraunhofer Institut für Fertigungstechnik und Materialforschung, Wiener Str. 12, D-28359 Bremen, Germany
A. Rehmet
Affiliation:
On leave from: I. Phys. Institut and SFB 345, Bunsenstr. 9, D-37073 Göttingen, Germany
A. Heesemann
Affiliation:
Now at: RELOG GmbH, Marconistr., D-24145 Kiel, Germany
Get access

Abstract

Diffusion in metallic glasses and in the supercooled liquid state is of considerable interest not only from the technological point of view but also in terms of fundamental science, particularly in connection with the glass transition. Within the framework of the mode coupling theory the glass transition is a kinetic phenomenon characterized by the arrest of viscous flow at a critical temperature T c well above the calorimetric glass transition temperature T g. Below T c the theory predicts cooperative hopping processes. We present results from isotope effect measurements which indeed confirm the highly collective nature of diffusion in metallic glasses and suggest cooperative hopping processes to be closely related to the universal low-frequency excitations as observed in recent molecular dynamic simulations. In accord with the mode coupling scenario these cooperative hopping processes are also observed in the supercooled liquid state of the new bulk metallic glasses well above T g. The reported kink in the Arrhenius plot for diffusion of various elements is shown to be related to structural changes above T g, e.g., an increase in free volume as probed by positron annihilation, but not to a change in the diffusion mechanism. Measurements of the activation volume of diffusion indicate that, depending on the structure of the glass, cooperative hopping may take place without assistance of thermally generated defects or via delocalized thermal defects. Moreover, we provide evidence of the existence of an opposite Kirkendall effect in interdiffusion between certain amorphous alloys that combine slow diffusion via thermal defects and fast direct diffusion.

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable