Abstract
Raman measurements on a superconducting superlattice with a 2:1 sequence of and layes revealed a new line in the spectral region around 320 , which is interpreted as a combination of odd lattice vibrations on the Y sublayers with a partial admixture of an even parity mode on the Pr sublayer, becoming Raman active in the superstructure. Its eigenvector is similar to a phonon from the interior of the Brillouin zone of the original lattice. No superconductivity-induced self-energy effects are observed for this phonon, although the IR-active counterparts of the individual Y sublayer vibrations in exhibit those effects.
- Received 5 March 1993
DOI:https://doi.org/10.1103/PhysRevLett.70.3804
©1993 American Physical Society