Phonon Dispersion Measurements of YBa 2Cu 3O 6.15 and YBa 2Cu 3O 6.95 by Time-of-Flight Neutron Spectroscopy
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.
J. Chung and T. Egami and R. J. McQueeney and M. Yethiraj and M. Arai and T. Yokoo and H. A. Mook and Y. Endoh and S. Tajima and C. D. Frost and F. Dogan, "Phonon Dispersion Measurements of YBa 2Cu 3O 6.15 and YBa 2Cu 3O 6.95 by Time-of-Flight Neutron Spectroscopy," Journal of Superconductivity, vol. 15, no. 5, pp. 327-330, Kluwer Academic Publishers, Oct 2002.
The definitive version is available at http://dx.doi.org/10.1023/A:1021057810930
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)
Article - Journal
© 2002 Kluwer Academic Publishers, All rights reserved.