Far-Infrared Properties of ab plane oriented YBa2Cu3O7-δ Academic Article uri icon

  •  
  • Overview
  •  
  • Research
  •  
  • Identity
  •  
  • Additional Document Info
  •  
  • View All
  •  

abstract

  • ABSTRACTPolycrystalline samples of YBa2Cu2O7-δ with a variety of surface treatments show differences in absolute reflectance and width of phonon lines. Samples that are not polished and are measured immediately after annealing have largely grains with the c axis normal to the surface. Such oriented samples show a gap-like depression of conductivity in the far infrared that sets in below the superconducting transition temperature but no true gap. Phonon lines at 195 cm−1 and at 155 cm−1 narrow in the superconducting state, in analogy with the effect of the electron phonon interaction in BCS superconductors. In the normal state the background conductivity is Drude like with a plasma frequency of 0.75 eV and a relaxation rate of 200 cm−1. The extrapolated far-infrared conductivity agrees with the measured dc conductivity.

publication date

  • 1987