Determination of valence of Cu in superconducting La2−x(Sr,Ba)xCuO4

E. E. Alp; G. K. Shenoy; D. G. Hinks; D. W. Capone II; L. Soderholm; H.-B. Schuttler; J. Guo; D. E. Ellis; P. A. Montano; M. Ramanathan

doi:10.1103/PhysRevB.35.7199

Determination of valence of Cu in superconducting La2−x(Sr,Ba)xCuO4

E. E. Alp, G. K. Shenoy, D. G. Hinks, D. W. Capone II, L. Soderholm, H.-B. Schuttler, J. Guo, D. E. Ellis, P. A. Montano, M. Ramanathan

DOI 10.1103/PhysRevB.35.7199 · Physical Review B

T1

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Abstract

The measurement of Cu K-edge x-ray absorption near-edge structure of monovalent, divalent, and trivalent copper oxides has been used to identify the presence of different valence of copper in the La2−x(Sr,Ba)xCuO4 (x=0.0–0.3) system. The results indicate the coexistence of Cu ii and Cu iii states in these compounds. Theoretical calculations based on a cluster of CuO4O2La8LaSr predict the presence of nearly degenerate electronic ground states representing nominally Cu ii and Cu iii configurations.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
La1.85Sr0.15CuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	36	Pressure not reported	unknown