Nonlinear acoustics at GHz frequencies in a viscoelastic fragile glass former.
Using a picosecond pump-probe ultrasonic technique, we study the propagation of high-amplitude, laser-generated longitudinal coherent acoustic pulses in the viscoelastic fragile glass former DC704. We observe an increase of almost 10% in acoustic pulse propagation speed at the highest optical pump fluence which is a result of the supersonic nature of nonlinear propagation in the viscous medium. From our measurement, we deduce the nonlinear acoustic parameter of the glass former in the gigahertz frequency range across the glass transition temperature.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA and Institut Molécules et Matériaux du Mans, UMR-CNRS 6283, Université du Maine, 72085 Le Mans, France.
Christoph
C
Klieber
Institut Molécules et Matériaux du Mans, UMR-CNRS 6283, Université du Maine, 72085 Le Mans, France and Laboratoire d'Acoustique de l'Université du Maine, UMR-CNRS 6613, Université du Maine, 72085 Le Mans, France.
Vitalyi E
VE
Gusev
Institut Molécules et Matériaux du Mans, UMR-CNRS 6283, Université du Maine, 72085 Le Mans, France.
Thomas
T
Pezeril
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Keith A
KA
Nelson