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Title: Phonon Dispersion Measurements of YBa2Cu3O6.15 and YBa2Cu3O6.95 by Time-of-Flight Neutron Spectroscopy

Journal Article · · Journal of Superconductivity
 [1];  [2];  [3];  [4];  [5];  [5];  [4];  [6];  [7];  [8];  [9]
  1. National Institute of Standards and Technology (NIST)
  2. University of Pennsylvania
  3. Ames Laboratory
  4. ORNL
  5. Institute of Materials Structure Science, Japan
  6. Tohoku University, Japan
  7. Superconductivity Research Laboratory, Japan
  8. ISIS Facility, Rutherford Appleton Laboratory
  9. University of Washington, Seattle

We measured the phonon dispersions of YBa{sub 2}Cu{sub 3}O{sub 6.15} and YBa{sub 2}Cu{sub 3}O{sub 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.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
978071
Journal Information:
Journal of Superconductivity, Vol. 15, Issue 5; ISSN 0896-1107
Country of Publication:
United States
Language:
English