Superconductivity

We have measured reflectivity over an energy range from E=`3meV to `3eV and a temperature range from T=10 to 300K in the CuO-plane of a series of twinned, c-axis oriented crystals each of which has dimensions roughly 2X2X. 1mm. The results vary from sample to sample and differ from those of other laboratories, probably due to compositional and structural differences.