The synthesis of superconducting Tl--Ca--Ba--Cu--oxide films by the reaction of spray deposited Ca--Ba--Cu--oxide precursors with Tl sub 2 O vapor in a two-zone reactor

Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1991.1415· OSTI ID:5623812

DeLuca, J A; Garbauskas, M F; Bolon, R B; McMullen, J G; Balz, W E; Karas, P L ^[1]

---

1. General Electric Corporate Research and Development, Schenectady, New York 12301 (USA)

Superconducting Tl--Ca--Ba--Cu--oxide films have been prepared on yttria stabilized zirconia substrates via the reaction of Tl{sub 2}O vapor with precursor Ca--Ba--Cu--oxide films prepared by the spray pyrolysis of a solution of the metal nitrates. The vapor reaction process, evaluated in both air and oxygen ambients, was carried out in a two-zone reactor which permitted the independent control of the temperatures of the sample and of a boat containing thallium oxide. Sample temperatures of 865--905 {degree}C and boat temperatures of 775--870 {degree}C were investigated. X-ray diffraction analysis of the best samples, which were prepared in an oxygen ambient at sample temperatures of 895--900 {degree}C and boat temperatures of 805--810 {degree}C, revealed the presence of a highly oriented Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10+{ital y}} phase with a trace of the Tl{sub 2}CaB{sub 2}Cu{sub 2}O{sub 8+{ital y}} phase. FWHM's of {similar to}2{degree} {theta} were obtained in x-ray rocking curve analyses of the oriented 2223 phase. {ital T}{sub {ital c}} (0) values of 95--105 K were measured for the better samples, and a zero field critical current density of 28 800 amps/cm{sup 2} was measured at 77 K for the best sample. SEM micrographs taken of the highest {ital J}{sub {ital c}} samples reveals a highly textured structure consisting of platelike crystals.

• OSTI ID: 5623812
• Journal Information: Journal of Materials Research; (USA), Vol. 6:7; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
SYNTHESIS
CALCIUM OXIDES
COPPER OXIDES
THALLIUM OXIDES
HIGH-TC SUPERCONDUCTORS
SPRAYED COATINGS
SUPERCONDUCTING FILMS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COATINGS
COPPER COMPOUNDS
FILMS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTORS
THALLIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication