Abstract
We show, using a proposed oxygen-defect structure for and a tight-binding model based on density-functional calculations, that the distribution of holes between planes and (fragmented) chains causes jumps and plateaus for the hole counts in the planes as a function of the nonstoichiometry, . These features can be correlated with the occurrence of the antiferromagnetic as well as the 60- and 90-K superconducting phases. Our findings are supportive of the view that the hole count is the controlling parameter for the superconductivity.
- Received 18 February 1988
DOI:https://doi.org/10.1103/PhysRevLett.60.2685
©1988 American Physical Society