Japanese Journal of Applied Physics · 1988 · 83 citations · 12 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid State PhysicsCrystal ChemistryInorganic MaterialsPerovskite MaterialsStrongly Correlated Electron SystemsSuperconducting MaterialsAnnealingAnnealing EffectsCuprate SuperconductorsHigh-temperature SuperconductorsSuperconducting CeramicsSuperconducting Critical TemperatureSuperconducting Properties
The effects of Ca 2+ substitution for Y 3+ and La 3+ substitution for Ba 2+ in YBa 2 Cu 3 O 7 on the structural and superconducting properties were studied to control the average copper charge. Single-phase tripled perovskites were obtained for 0≦ x ≦0.2 and 0≦ x ≦1.0 for Ca and La doped series, respectively. A slight decrease of T c with increasing x was found for small x values for both kinds of substituted specimens prepared by furnace cooling in air. Oxygen annealing experiments were also carried out. These suggested that the superconduction in the Y-Ba-Cu-O system cannot be interpreted only by oxygen content or average copper charge.
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Substitution for copper in a high-Tc superconductor YBa2Cu3O7–δ
Y. Maeno, Tsukasa Tomita, M. Kyogoku et al. · Nature · 1987 · 385 citations
Superconductivity in YBa2−<i>x</i>Sr<i>x</i>Cu3O7−δ
B. W. Veal, W. K. Kwok, A. Umezawa et al. · Applied Physics Letters · 1987 · 212 citations