Europhys. Lett.
Volume 68, Number 2, October 2004
Page(s) 226 - 232
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 October 2004
Europhys. Lett., 68 (2), pp. 226-232 (2004)
DOI: 10.1209/epl/i2004-10193-6

Indications for an "excess wing" in metallic glasses from the mechanical loss modulus in $\chem{Zr_{65}Al_{7.5}Cu_{27.5}}$

P. Rösner1, K. Samwer1 and P. Lunkenheimer2

1  I. Physikalisches Institut, Georg-August-Universität Göttingen Tammannstr. 1, 37077 Göttingen, Germany
2  Experimentalphysik V, Institut für Physik, Universität Augsburg Universitätsstr. 2, 86135 Augsburg, Germany

received 11 June 2004; accepted in final form 24 August 2004

The temperature-dependent complex shear modulus G* of an amorphous, 300 $\un{nm}$ thick $\chem{Zr_{65}Al_{7.5}Cu_{27.5}}$ film is measured using a double-paddle oscillator as a substrate, oscillating in its torsional eigenmode at about 5440 $\un{Hz}$. At high temperatures, the loss modulus is dominated by viscous flow that leads to an $\alpha$-relaxation peak in the temperature domain. We calculate this peak for our metallic system using the Havriliak-Negami function for the mechanical loss in combination with the Vogel-Fulcher-Tammann equation to describe the temperature-dependent characteristic relaxation time. In the vicinity of the glass transition, we observe a clear experimental deviation from this calculated $\alpha$-process, which we consider as first indication for the existence of an "excess wing" in metallic systems.

64.70.Pf - Glass transitions.
62.40.+i - Anelasticity, internal friction, stress relaxation, and mechanical resonances.
61.25.Mv - Liquid metals and alloys.

© EDP Sciences 2004