We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+δ, in which the phase separation observed in La2CuO4+δ is suppressed. A phase diagram in the T-δ plane is given for La1.9Bi0.1CuO4+δ with excess oxygen. For very small δ values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly at δ ∼ 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04<δ<0.11. This is clear evidence that high-Tc superconductivity also appears in the tetragonal phase.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)