RT info:eu-repo/semantics/article T1 Communication: Are metallic glasses different from other glasses? A closer look at their high frequency dynamics A1 Serrano GutiƩrrez, Jorge AB Using high resolution inelastic x-ray scattering we studied the collective dynamics of the Pd77Si16.5Cu6.5 metallic glass, focusing on the energy-momentum region where the boson peak appears. The dispersion relation and the width of the acoustic excitations are determined showing how the longitudinal acoustic modes maintain their dispersive character for frequencies well above the boson peak frequencies. Moreover, we prove that close to these frequencies there is a softening of the apparent sound speed indicating a failure of the Debye continuum approximation at the boson peak frequencies and challenging previous results on other metallic glasses. PB American Institute of Physics YR 2011 FD 2011 LK https://uvadoc.uva.es/handle/10324/65237 UL https://uvadoc.uva.es/handle/10324/65237 LA eng NO J. Chem. Phys. 135, 101101 (2011) DS UVaDOC RD 21-may-2024