Abstract
We report Raman measurements on c-axis-oriented high- / superlattices. The assignment of the observed phonon lines is obtained from a comparison of the Raman spectra of these superlattices, bulk and , and also of an (Y/Pr) mixed crystal. Vibrational peaks were found corresponding to confined phonons as well as extended excitations. We find also a pronounced softening of the -like phonon localized in the Y layers (out-of-plane bending vibration of -plane oxygen) below the superconducting transition temperature , a property characteristic of superconductors, while phonons localized in show no such effect.
- Received 2 June 1992
DOI:https://doi.org/10.1103/PhysRevB.46.14017
©1992 American Physical Society