The thermal stability of the superconducting phase of nominal composition YBa 2Cu 3O 7-x-sintered pellets has been studied with respect to different temperatures (ranging from 300 to 950° C), time (ranging from 1 to 72 h), oxygen partial pressure (from 4 Pa to 1 atm) and carbon dioxide partial pressure (from 10 -4 Pa to 1 atm). Annealed samples were characterized by X-ray diffraction analysis, optical microscopy, and resistive measurements of the superconductive transition temperature. A stability field of the orthorhombic and tetragonal phases was obtained, showing a region of coexistance. The decomposition of the 1 2 3 phase is found to be strongly influenced by the presence of a small amount of CO 2 (1 p.p.m.) in the sintering atmosphere. A sintering process is proposed to avoid the formation of by-products. © 1990 Chapman and Hall Ltd.
A study on the stability of superconducting yttrium barium copper oxide (YBa2Cu3O7-x) phase / G., Dell'Agli; Marino, Ottavio; G., Mascolo; Pernice, Pasquale; A., Di Chiara; Pepe, GIOVANNI PIERO; SCOTTI DI UCCIO, Umberto. - In: JOURNAL OF MATERIALS SCIENCE. MATERIALS IN ELECTRONICS. - ISSN 0957-4522. - STAMPA. - 1:(1990), pp. 20-24. [10.1007/BF00716011]
A study on the stability of superconducting yttrium barium copper oxide (YBa2Cu3O7-x) phase
MARINO, OTTAVIO;PERNICE, PASQUALE;PEPE, GIOVANNI PIERO;SCOTTI DI UCCIO, UMBERTO
1990
Abstract
The thermal stability of the superconducting phase of nominal composition YBa 2Cu 3O 7-x-sintered pellets has been studied with respect to different temperatures (ranging from 300 to 950° C), time (ranging from 1 to 72 h), oxygen partial pressure (from 4 Pa to 1 atm) and carbon dioxide partial pressure (from 10 -4 Pa to 1 atm). Annealed samples were characterized by X-ray diffraction analysis, optical microscopy, and resistive measurements of the superconductive transition temperature. A stability field of the orthorhombic and tetragonal phases was obtained, showing a region of coexistance. The decomposition of the 1 2 3 phase is found to be strongly influenced by the presence of a small amount of CO 2 (1 p.p.m.) in the sintering atmosphere. A sintering process is proposed to avoid the formation of by-products. © 1990 Chapman and Hall Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
