Nanoscale coherent intergrowthlike defects in a crystal of La1.9Ca1.1Cu2O6+delta made superconducting by high-pressure oxygen annealing

Article

关键词: POWDER DIFFRACTION DATA;    X-RAY-ABSORPTION;    GROWTH;    REFINEMENT;    CUPRATE;    OXIDES;   

DOI  :  10.1103/PhysRevB.90.134518

来源: SCIE

【 摘 要 】

Superconductivity with T-c = 53.5 K has been induced in a large La1.9Ca1.1Cu2O6 (La-2126) single crystal by annealing in a high partial pressure of oxygen at 1200 degrees C. Using transmission electron microscopy techniques, we show that a secondary Ca-doped La2CuO4 (La-214) phase, not present in the as-grown crystal, appears as a coherent intergrowthlike defect as a consequence of the annealing. A corresponding secondary superconducting transition near 13 K is evident in the magnetization measurement. Electron energy-loss spectroscopy reveals a pre-edge peak at the O-K edge in the superconducting La-2126 phase, which is absent in the as-grown crystal, confirming the hole doping by interstitial oxygen.

【 授权许可】

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