Formation of orthorhombic YBa2Cu3O7−x at 900–1020°C in air from a precursor containing BaCuO2.5

✍ Scribed by Shome N. Sinha; Hai Woong Park

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 910 KB
• Volume: 221
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90234-8

✦ Synopsis

Orthorhombic YBa2Cu3OT_x was obtained when a synthesized precursor containing Y203, BaCuO2.5 and CuO was heated rapidly to 950-1020°C in air, held for 30 min, and quenched. During DTA at 20°C/min, the BaCuO2.5 in the precursor decomposed at 838°C. The BaCuO2.5 constituent did not completely decompose during heating at > 50°C/min up to 1020°C and 10 min holding at 950-54°C and 1020°C, when powder or bulk orthorhombic YBa2Cu307_x formed. Thirty minutes of processing of the precursor mixed with 5 or 10 wt.% silver or excess copper at 1020 ° C in air resulted in superconductors with > 10 ~tm size voids beneath dense surfaces.