Experimental Cu 3d electronic structure in high-T c La 1.85Ba 0.12CuO 4-x and YBa 2Cu 3O 8-x superconductors

Abstract

Soft x-ray emission spectroscopy has been used to study the local Cu 3d density of states in two high-T c superconducting oxides: La 1.85Ba 0.12CuO 4-x and YBa 2Cu 3O 8-x. It is found that the Cu 3d states lie at 3.5 eV binding energy and have a low density of states at the Fermi level. Comparison with available local-density-functional calculations suggests that the electronic structure of these compounds may be treated within the frame-work of the one-electron approximation.