LOCAL CHEMICAL-COMPOSITION OF HGBACACUO HIGH-TEMPERATURE SUPERCONDUCTORS

The microchemical composition and the electronic structure of the two superconductors HgBa2Ca2Cu3O8+delta(Hg-1223) and HgBa2CaCu2O6+delta (H g-1212) were analyzed with the technique of photoemission with high sp atial resolution. This enabled primary spectral peaks to be separated from their satellites due to local charging induced by the primary pho ton beam. Each sample contains superconducting and impurity phases wit h inhomogeneous spatial distributions. The oxygenation-induced increas e in the critical temperature is related to a increase in the Cu-O pla ne carrier concentration.