Title

Phonon Dispersion Measurements of YBa 2Cu 3O 6.15 and YBa 2Cu 3O 6.95 by Time-of-Flight Neutron Spectroscopy

Abstract

We measured the phonon dispersions of YBa 2Cu 3O 6.15 and YBa 2Cu 3O 6.95 by time-of-flight inelastic neutron scattering. The in-plane bond-stretching modes in the metallic phase showed a distinct a-b plane anisotropy beyond what is expected for structural origin. Such anisotropy in the longitudinal optical modes, which is absent in the TO, suggests strong in-plane anisotropy in the underlying electronic structure. Apical oxygen bond-stretching modes showed a large frequency change between the insulating and the metallic phases. This large softening also is beyond structural origin, and suggests the effect of local electronic environment.

Department(s)

Materials Science and Engineering

Keywords and Phrases

In-plane anisotropy; Metallic phases; Phonon dispersion; Y-based cuprates; Anisotropy; Electronic structure; Energy transfer; Infrared spectroscopy; Phonons; Raman spectroscopy; Single crystals; Thermal effects; Neutrons

International Standard Serial Number (ISSN)

8961107

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2002 Kluwer Academic Publishers, All rights reserved.

Share

 
COinS