Superconductivity above 30 K in [(Bi1−xMox)0.33Cu0.67]Sr2YCu2Oy: Appearance of superconductivity by transfer of holes from a block layer to a CuO2 layer
Shiro Kambe, Eiji Sato, Takahiro Akao, Shigetoshi Ohshima, Katsuro Okuyama, Rika Sekine
DOI 10.1103/PhysRevB.60.687 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
Attention has been paid to a (Bi0.33Cu0.67)Sr2YCu2Oy compound for its uncertain superconductivity in spite of having a large Cu valence. By conducting combined experiments of iodometry, and chlorinemetry, Hall voltage measurement, Rietveld analysis, and a Discrete vibrational (DV)−Xα calculation for (Bi0.33Cu0.67)Sr2YCu2Oy, evidence of localization of holes in a (Bi0.33Cu0.67)Oy block layer was found. Those experiments suggest that about 90% of holes estimated from the Mott-Hubbard theory are localized. DV−Xα calculation revealed that the localized holes in (Bi0.33Cu0.67)Sr2YCu2Oy are not located at the apical or planar oxygen of a CuO2 layer but in the block layer. In order to transfer the localized holes from the block layer to the CuO2 layer, substitution of Mo for Bi was performed, resulting in an increase of the itinerant holes from 10 to 60 %. A bond valence sum calculation also suggested the transfer of holes from the block layer to the CuO2 layer with changes in occupancies of the oxygen sites in the block layer. Eventually, in a range of x>~0.55, it showed superconductivity above 30 K. We also discuss the origin of nonsuperconductivity of cuprates with a high Cu valence.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| (Bi1-xMox)0.33Cu0.67Sr2YCu2Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 30 | Pressure not reported | onset |
| (Bi1-xMox)0.33Cu0.67Sr2YCu2Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 37 | Pressure not reported | onset |
| Bi0.5Cu0.5Sr2Y0.8Cu2.2O0.95 Archive — disputed claim Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 68 | Pressure not reported | unknown |
| (Bi0.3Cu0.7)Sr2YCu2Oy Archive — disputed claim Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 20 | Pressure not reported | unknown |
Similar papers
Superconductivity above 100 K by Pr substitution in the two-copper-layer Bi-Pb-Sr-Ca-Cu-O system
similarity 0.93A. Gama et al.
Source status unknown — claims are unverified
Influence of lead on the formation of the 110-K superconducting phase in the Bi-Sr-Ca-Cu-O compounds
similarity 0.92E. Chavira et al.
Source status unknown — claims are unverified
Effect of annealing on the superconductivity of Bi2Sr2CaCu2Oy single crystals
similarity 0.92Wenbin Wu et al.
Source status unknown — claims are unverified
Effect of compositional variation and annealing in oxygen on superconducting properties of Y1Ba2Cu3O8−y
similarity 0.92A. J. Panson et al.
Source status unknown — claims are unverified
Superconductivity and microstructure of YSr2Cu3O6.875
similarity 0.92O. I. Lebedev et al.
Source status unknown — claims are unverified
Single-phase 60-K bulk superconductor in annealed Ba2YCu307−δ(0.3<δ<0.4) with correlated oxygen vacancies in the Cu-O chains
similarity 0.92R. J. Cava et al.
Source status unknown — claims are unverified