D- ANALYSIS OF THE ELECTRONIC RAMAN DATA OF YBA2CU3O7-DELTA AND OTHERCUPRATES(S WAVE SUPERCONDUCTIVITY )

After briefly recalling the d + s model valid for some anisotropic hig h T-c superconductors, we present a theory of electronic Raman spectra , in that model and then compare it with new experimental data obtaine d for an overdoped Y123 single crystal. The d + s model appears to des cribe satisfactorily the experimental results, indicating a possible d oping dependence of the mixing ratio. We note that the Raman spectrum of the overdoped Bi2212 could also be accounted for by the d + s super conductivity model. The case of Hg1212 (or Hg1223) is reexamined. It a ppears that the spontaneous breakdown of d-wave symmetry may be rather universal in high T-c cuprates.