Superconducting phases of La2CuO4+δ prepared by electrochemical oxidation at ambient temperature
H. H. Feng, Z. G. Li, P. H. Hor, S. Bhavaraju, J. F. DiCarlo, A. J. Jacobson
DOI 10.1103/PhysRevB.51.16499 · 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
Superconducting phases in La2CuO4+δ prepared at ambient temperature by electrochemical oxidation have been investigated for the nominal composition range 0<δ<0.1. Consistent with previous reports, a stable superconducting phase with Tc∼32–34 K is observed for δ≤0.05. In contrast, samples with δ≳0.05 are found to be unstable either at room temperature or upon annealing between 25 °C and 110 °C. All phases with Tc higher than 34 K, such as Tc∼45 K phase, are metastable and only accessible under highly nonequilibrium intercalation conditions. A phase with Tc=15 K is also observed at a nominal hole concentration of p∼0.125, indicating that all of the observed Tc depressions in the cation substituted La2−x(Sr,Ba)xCuO4 and anion doped La2CuO4+δ at p∼0.125 are electronically driven and are of a common origin.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| La2CuO4+δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 32 | Pressure unresolved | onset |
| La2CuO4+δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 45 | Pressure unresolved | onset |
| La2CuO4+δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 15 | Pressure unresolved | onset |
| La2-x(Sr,Ba)xCuO4 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 15 | Pressure not reported | unknown |
Similar papers
Superconducting properties in La2CuO4+δ with excess oxygen
similarity 0.96Toshikazu Hirayama et al.
Source status unknown — claims are unverified
Synthesis of bulk superconducting La2CuO4 in an electrochemical cell
similarity 0.95J. C. Bennett et al.
Source status unknown — claims are unverified
Superconductivity in lanthanum cuprates: A layered-electron-gas model
similarity 0.95Dinesh Varshney & R. K. Singh
Source status unknown — claims are unverified
Superconducting properties of La2−xBaxCuO4
similarity 0.95A. R. Moodenbaugh et al.
Source status unknown — claims are unverified
Pressure dependence of the superconducting transition temperature of superoxygenated La2CuO4+δ
similarity 0.95J. E. Schirber et al.
Source status unknown — claims are unverified
Structural instability in single crystals of the high-Tc superconductor La2−x Srx CuO4
similarity 0.95Urs Geiser et al.
Source status unknown — claims are unverified