Chain-fragment doping and the phase-diagram of yba2cu3o7-x

TLDR: Un modele de structure de defaut du compose non stœchiometrique, combine a l'approximation des liaisons fortes, rend compte des transitions supraconductrice and magnetique du materiau, mettant ainsi en evidence l'importance des trous dans l'sapparition des phases suprachonductrice et antiferromagnetique.

Abstract: We show, using a proposed oxygen-defect structure for ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}x}$ 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, $x$. 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.