High-Frequency Transverse Phonons in Metallic Glasses

December 15, 2020
High-Frequency Transverse Phonons in Metallic Glasses
Top: Phonon Q-dependent generalized density of states from INS data. Bottom: Corresponding neutron-weighted MD simulations.

Scientific Achievement

It is shown in a Zr-Cu-Al metallic glass that transverse phonon modes exist in the high-frequency regime and the transverse phonon width follows the static structure factor.

Significance and Impact

The observed universal link between structure and dynamics in glasses, combined with the importance of transverse phonons in physical properties of these materials suggests a new approach is needed for a fundamental understanding of the glass transition.

Research Details

  • Inelastic neutron scattering (INS) allowed measurements at high momentum transfer, where x-ray inelastic scattering would be reduced by the atomic form factor.
  • Classical molecular dynamics (MD) simulations were used to compare to experimental data.
  • The static structure factor was measured with both x-ray (BL 11-ID-C at APS) and neutron (NOVA at J-PARC) diffraction.

“Observation of High-Frequency Transverse Phonons in Metallic Glasses,” 
X. Y. Li, H. P. Zhang, S. Lan, D. L. Abernathy, T. Otomo, F.W. Wang, Y. Ren, M. Z. Li, and X.-L. Wang
Physical Review Letters, 124, 225902 (2020).