Structural anomalies at the disappearance of superconductivity in Ba2YCu3O7−δ: Evidence for charge transfer from chains to planes

✍ Scribed by R.J. Cava; B. Batlogg; K.M. Rabe; E.A. Rietman; P.K. Gallagher; L.W. Rupp Jr

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 356 KB
• Volume: 156
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(88)90015-9

✦ Synopsis

In systematic studies of oxygen-deficient Ba2YCu307_~, we have found that a structural anomaly occurs at the composition where bulk superconductivity disappears. The observed step-like increase in the c lattice parameter, when associated with changes in the atomic positions within the unit cell, indicates that superconductivity is lost due to a charge redistribution from the copperoxygen chains to the copper-oxygen planes. This is microscopic experimental evidence establishing the role of secondary structural elements in the layered copper-oxide high-To superconductors.