Abstract
The Boson peak (BP), an excess of vibrational density of states, is ubiquitous for amorphous materials and is believed to hold the key to understanding the dynamics of glass and glass transition. Previous studies have established an energy scale for the BP, which is ~ 1-10 meV or ~ THz in frequency. However, so far, little is known about the momentum dependence or spatial correlation of the BP. Here, we report the observation of the BP in model Zr-Cu-Al metallic glasses over a wide range of momentum transfer, using inelastic neutron scattering, heat capacity, Raman scattering measurements, and molecular dynamics (MD) simulations. The BP energy is largely dispersionless; however, the BP intensity is found to scale with the static structure factor. Additional MD simulations with a generic Lennard-Jones potential confirm the same. Based on these results, an analytical expression for the dynamic structure factor is formulated for the BP excitation. Further analysis of the simulated disordered structures suggests that the BP is related to local structure fluctuations (e.g., in shear strain). Our results offer insights into the nature of the BP and provide guidance for the development of theories of amorphous materials.
| Original language | English |
|---|---|
| Article number | 860 |
| Journal | Nature Communications |
| Volume | 17 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2026 |
Funding
X.L.W., X.Y.L., C.H.H., and L.R.F. thank the support by the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. JLFS/P-101/24), a grant at City University of Hong Kong (Project No. 9229019), and Croucher Senior Research Fellowship (CityU Project No. 9500008). X.L.W. and S.L. acknowledge support by the NSFC/RGC Joint Research Scheme (No. N_CityU173/22) and Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology (grant no. 2019B121205003). S.L. acknowledges support by the National Natural Science Foundation of China (No. 12261160364, 52222104). M.Z.L. acknowledges support by the National NSFC (Nos. 52031016, 12574220, and 51631003). H.P.Z. acknowledges support by the National NSFC (Nos. 52301214 and 52192601). The neutron scattering experiments were carried out at the Spallation Neutron Source, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy, under contract No. DE-AC05-00OR22725 with Oak Ridge National Laboratory.