Observation of Superconductivity in Nb2O5 Doped YBa2Cu3O7-δ Compound by Rapid Quenching
Abstract
Superconductivity in YBCO compound depends on its oxygen stoichiometry and to keep the oxygen stoichiometry at the desired level, slow cooling of samples in oxygen atmosphere was reported to be essential. In our present work it is found that the widely accepted procedure of slow cooling at a rate of 1°C/min or annealing at 600°C for several hours after high temperature sintering is not essential to obtain high temperature superconductivity if the YBCO samples are doped with small amount of Nb2O5. Superconductivity could still be obtained by directly quenching the doped specimen in oxygen from sintering temperature. Tetragonal to orthorhombic transformation takes place in seconds in doped samples indicates that the rate of absorption of oxygen has tremendously increased by the Nb2O5 addition.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- March 1991
- DOI:
- 10.1143/JJAP.30.L458
- Bibcode:
- 1991JaJAP..30L.458P
- Keywords:
-
- Copper Oxides;
- High Temperature Superconductors;
- Niobium Oxides;
- Rapid Quenching (Metallurgy);
- Superconductivity;
- Yttrium Oxides;
- Barium Oxides;
- Phase Transformations;
- Stoichiometry;
- Solid-State Physics