Abstract
We report a systematic lattice dynamics study of films and nanoislands by in situ nuclear inelastic scattering on and ab initio theory. The Eu-partial phonon density of states of the nanoislands exhibits anomalous excess of phonon states at low and high energies, not present in the bulk and at the surface. We demonstrate that atomic vibrations along the island-substrate interface give rise to phonon states both at low and high energies, while atomic vibrations across the island-island interface result in localized high-energy phonon modes.
- Received 27 July 2016
DOI:https://doi.org/10.1103/PhysRevLett.117.276101
© 2016 American Physical Society