Yttrium Substitution for Calcium in Tl2Ba2Ca2Cu3O10+δ: Preparation and Study of Superconducting Phases

✍ Scribed by B. Himmerich; H. Sabrowsky; D.-N. Peligrad; M. Rosenberg

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 355 KB
• Volume: 108
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1025

✦ Synopsis

Starting from the nominal compositions (\mathrm{Tl}{2} \mathrm{Ba}{2} \mathrm{Ca}{2-x} \mathrm{Y}{x} \mathrm{Cu}{3} \mathrm{O}{10+\delta}) after heat treatments in Ar atmosphere in gold sealed tubes, both superconducting phases " 2223 " and " 2212 " and the paramagnetic phase Bad (un ()_{2}) were present for zero and low (Y) concentrution ( (0 \leq x \leq 0.3) ). The decrease of the critical temperature from 126 to (118 \mathrm{~K}) for the 2223 phase and from 114 to (100 \mathrm{~K}) for the 2212 phase was considered as evidence for (Y) substitution on Ca sites for low (x) values and corresponding reduction of the hole concentration per (\mathrm{Cu}) atom. Higher (Y) concentrations ((x \geq 0.3)) destabilize the superconducting phases. o) 1994 Academic Press, Inc.