Electronic structure of Cu-O chains in the high-Tc superconductor YBa2Cu3O7

H. Chen; J. Callaway; P. K. Misra

doi:10.1103/PhysRevB.38.195

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Electronic structure of Cu-O chains in the high-Tc superconductor YBa2Cu3O7

H. Chen, J. Callaway, P. K. Misra

DOI 10.1103/PhysRevB.38.195 · Physical Review B

T1

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Abstract

The electronic structure of Cu-O chains in the high-Tc superconductor YBa2Cu3O7 is investigated by self-consistent, all-electron, spin-polarized cluster calculations in the local-spin-density approximation for the cluster Ba4Cu2O7. Four different charge states are considered. No localized moments are present on the Cu atoms in any of the charge states considered. The ground state of the cluster shows strong covalent bonding between the copper and oxygen atoms. Transition-state calculations are made to determine electronic relaxation occurring in photoemission, to calculate the effective Hubbard interaction parameter U for both copper and oxygen sites, and to find the energy required for charge transfer between oxygen and copper atoms. The results are compared with experiment.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBa2Cu3O7 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	90	Pressure not reported	onset
La2CuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	40	Pressure not reported	onset