Optical Properties of High T sub c Superconductors
11 June 1987
We present far-induced reflectivity spectra of seven samples of ceramic superconductors in the Ba-Y-Cu-O system with transition temperatures near 93K. We find superconducting gas structures on the basis of which we estimate the ratio of twice the average gap to the transition temperature to be consistent with 3.5, but possibly higher. Questions of normal state characterization preclude a definitive analysis.