Comparison of the Electrodynamic Properties of Sintered YBa2Cu3O(7-y) and La(1.85)Sr(0.15)CuO(4-y)

摘要

The reflectivity in the superconducting and normal sites of YBa2Cu307-y has been reproduced with the effective-medium theory plus an anisotropic dielectric function and the Mattis-Bardeen conductivity with a gap value 2 delta/kBTc=2.5 to 2.7. We find that the lowest IR-active phonon polarized in the high-conductivity plane produces structure in the superconducting gap, the lowest-frequency phonon perpendicular to the plane is overdamped, and the electronic susceptibility is more isotropic for YBa2Cu307-y than for La1.85Sr0.15Cu04-y.