Role of the Cu-O charge-transfer energy in the superconductivity of cuprates: evidence from Cu 2p core-level spectroscopy and theory

Abstract

Based on Cu 2p core-level spectroscopy and theoretical calculations, it has been demonstrated that the Cu-O charge-transfer excitation energy which determines the Cu 2p satellite intensity also plays a crucial role in the superconductivity of cuprates. The relative intensity of the satellite generally decreases with an increase in the T_c or in the hole concentration in a given series of cuprate superconductors. In the case of Bi₂Ca_1−xR_xSr₂Cu₂O_8+δ (R=rare earth), the satellite intensity goes through a minimum around the same composition where the hole concentration as well as the T_c show maxima.