Oxygen pressure, the key factor for optimization of superconductivity in the 1212-phase Pb1−xSr2Ca0.5Y0.5Cu2+xO7±δ

✍ Scribed by A. Maignan; T. Rouillon; D. Groult; J. Provost; C. Michel; B. Raveau; R.S. Liu; P.P. Edwards

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 462 KB
• Volume: 177
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(91)90503-q

✦ Synopsis

The influence of oxygen pressure upon superconducting properties of lead-based 1212 copper oxides Pbt_xSr2Cao.sYo.sCu2+xO7+ 6 has been investigated as a function of time and annealing temperature. Annealings of (Pbo.7Cuo.3) Sr2Cao.sYo.5Cu207 + 6 at 400 ° C for 10 h show thai this material becomes superconductive as the oxygen pressure reaches 10 bar, the critical temperature being increased from 0 to 29 K. The maximum value of Tc=42 K is obtained for an oxygen pressure ranging between 40 and 60 bar. Annealing at 20 bar for 65 h show that Tc increases up to an annealing temperature of 500°C and decreases abruptly beyond this temperature.