Raman scattering from high-Tc superconductors.

Raman scattering experiments from high-1; superconductors of the RBa2Cu307-~ type, with R Y, Pr, Nd, Eu, Gd, Dy, and Yb, are reported. Because of the great difBculty in obtaining single-phase samples, spectra from all starting compounds and other known phases of Y-Ba-Cu are presented. This systematic approach has allowed the identi6cation of the lines observed in Raman spectra of the superconducting compounds as well as those of impurity phases. The lines originating from the superconducting yttrium compound were investigated as a function of quench temperature, and oxygen de5ciency. Polarization studies on single crystals are also presented.