High-Tc Superconducting Cuprates, (Ce,Y)sO2s-2Sr2(Cu2.75Mo0.25 )O6+[delta] : Tc-increase with apical Cu-O decrease at constant Cu-O planar distance

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Journal Title
Journal ISSN
Volume Title
School of Chemical Technology | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2014
Major/Subject
Mcode
Degree programme
Language
en
Pages
012031/1-4
Series
Journal of Physics: Conference Series, Volume 507, Issue 1
Abstract
Evidence for high-Tc cuprate superconductivity is found in a region of the phase diagram where non-superconducting Fermi liquid metals are expected. Cu valences estimated independently from both XANES measurements and bond valence sum calculations are greater than 2.25 and are in close agreement with each other for structures of the homologous series given in the title with s = 1, 2, 3, 4 and 5. Two questions arise from the present perspective: 1) Is all the action in the CuO2 layers? 2) Is there superconductivity beyond the usual dome? The record short apical oxygen distance found in the homologous series especially in the s = 1 member, at odds with the current theory, suggests the possibility of a new pairing mechanism. The apical Cu-O distance in the s = 1 member decreases upon oxygenation from 2.29 to 2.15 dot A while the Cu valence increases to 2.45 dot A.
Description
Keywords
cuprate, superconductivity
Citation
Marezio, M & Chmaissem, O & Bougerol, C & Karppinen, Maarit & Yamauchi, H & Geballe, T H. 2014. High-Tc Superconducting Cuprates, (Ce,Y)sO2s-2Sr2(Cu2.75Mo0.25 )O6+[delta] : Tc-increase with apical Cu-O decrease at constant Cu-O planar distance. Journal of Physics: Conference Series. Volume 507, Issue 1. 012031/1-4. ISSN 1742-6588 (printed). DOI: 10.1088/1742-6596/507/1/012031.