| Popis: |
We report the high temperature behaviour of single-phase YBa2Cu3O9 − y. This compound reveals superconductivity above 90 K. We performed high temperature (20–960 °C) resistivity measurements, differential thermal analysis and thermogravimetric analysis investigations. It was found that substantial oxygen depletion occurred above 420°C. The oxygen content changed reversibly with temperature at ambient pressure. The second-order-like transition around 650 °C, observed by differential thermal analysis, is an orthorhombic-tetragonal rearrangement of the lattice. These results are important for optimizing the processing conditions of this new class of high Tc superconducting compounds. |
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