Indications for an "excess wing" in metallic glasses from the mechanical loss modulus inP. 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 thick film is measured using a double-paddle oscillator as a substrate, oscillating in its torsional eigenmode at about 5440 . At high temperatures, the loss modulus is dominated by viscous flow that leads to an -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 -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