Phonon confinement and interface lattice dynamics of ultrathin high-k rare earth sesquioxide films: the case of Eu₂O₃ on YSZ(001).

ABSTRACT: The spatial confinement of atoms at surfaces and interfaces significantly alters the lattice dynamics of thin films, heterostructures and multilayers. Ultrathin films with high dielectric constants (high-k) are of paramount interest for applications as gate layers in current and future integrated circuits. Here we report a lattice dynamics study of high-k Eu₂O₃ films with thicknesses of 21.3, 2.2, 1.3, and 0.8 nm deposited on YSZ(001). The Eu-partial phonon density of states (PDOS), obtained from nuclear inelastic scattering, exhibits broadening of the phonon peaks accompanied by up to a four-fold enhancement of the number of low-energy states compared to the ab initio calculated PDOS of a perfect Eu₂O₃ crystal. Our analysis

SUBMITTER: Stankov S 

PROVIDER: S-EPMC9419856 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature