| 摘要 |
The present invention comprises novel superconducting materials exhibiting superconductivity at temperatures exceeding 90 K. with chemical formula TlaPbbCacSrdReCufOg where R=Y or the lanthanide rare earth elements and where 0.3</=a,b</=0.7, 0.05</=c</=1.1,2-c</=d</=1.95, 0.05</=e</=1, 1.9</=f</=2.1 and 6.5</=g</=7.5. These compounds, which are layered perovskite-like oxides, exhibit a high chemical stability, form readily into nearly single phase, do not require adjustment of oxygen stoichiometry after synthesis and compositions may be chosen allowing superconductivity at temperatures exceeding 100 K. A preferred form of the superconducting materials is the range of compositions given by the chemical formulaTl0.5+xPb0.5-xCa1-ySr2-zRy+zCu2O7+/- delta where 0</=x, 8</=0.3, 0</=y</=0.95, 0.05</=z</=1-y of which a preferred form isTl0.5+xPb0.5-xCa0.8+x+zSr2-zR0.2-xCu2O7+/- delta exemplified by Tl0.5Pb0.5CaSr1.8La0-2Cu2O7+/- delta where 0</= delta </=0.1.
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