Japanese Journal of Applied Physics · 1987 · 78 citations · 10 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid State PhysicsInorganic SpectroscopyMagnetism In SolidsStrongly Correlated Electron SystemsSuperconducting MaterialsX-ray CrystallographyCuprate SuperconductorsHigh-temperature SuperconductivityHigh-temperature SuperconductorsOxygen VacanciesOxygen Vacancies In Metal OxidesSuperconducting PropertiesTetragonal SystemX-ray Absorption Spectroscopy
The valency of Cu ions in the orthorhombic and tetragonal phases of high- T c superconductor Ba 2 YCu 3 O y (6.22< y <6.96) has been studied by near-edge X-ray absorption spectroscopy. The results indicate that the Cu valency at Cu 1 sites on the z =1/2 plane is strongly correlated with the high- T c (90 K) superconductivity, while the Cu valency of Cu 2 sites on the basal planes affects the low- T c (50-60 K) superconductivity of the orthorhombic phase.
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Evidence for superconductivity above 40 K in the La-Ba-Cu-O compound system
C. W. Chu, P. H. Hor, R. L. Meng et al. · Physical Review Letters · 1987 · 1.5K citations · Full text
High T<sub>c</sub>Superconductivity of La-Ba-Cu Oxides
Shin‐ichi Uchida, H. Takagi, K. Kitazawa et al. · Japanese Journal of Applied Physics · 1987 · 490 citations