Superconducting properties of magnetron sputtered high T/sub c/ thin films containing oxide compounds of yttrium, bismuth, or thallium

Conference · Wed Mar 01 04:00:00 EST 1989 · IEEE Trans. Magn.; (United States)

OSTI ID:6085678

Kang, J H; Kampwirth, R T; Gray, K E

The authors have used multiple source magnetron sputtering to prepare thin films of Y-Ba-Cu-O, Bi-Ca-Sr-Cu-O, and Tl-Ca-Ba-Cu-O on (100) SrTiO/sub 3/, (100) MgO, and ZrO/sub 2/-9%Y/sub 2/O/sub 3/ substrates. Y-Ba-Cu-O films grow best on SrTiO/sub 3/ with mostly an a-axis orientation. Stoichiometry, particularly the Ba/Ca ratio must be within 2% of the correct value to obtain narrow ..delta..T/sub c/ transitions. Conversely the 80K phase of Bi-Ca-Sr-Cu-O films grows best on MgO substrates and has a predominant c-axis orientation. The requirements on composition are less stringent, however, the annealing temperature must be held within a narrow around 865/sup 0/C to obtain the best films. The best films of Tl-Ca-Ba-Cu-O compounds are grown on (100) oriented and polycrystalline ZrO/sub 2/ substrates. The highest transition temperature, T/sub c0/, where the resistance goes zero is about 114K in the Tl/sub 2/Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ phase and 100-105K in Tl/sub 2/Ba/sub 2/Ca/sub 1/Cu/sub 2/O/sub x/ and Tl/sub 1/Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ phase samples. The upper critical field measurements show high anisotropies in the critical field slopes (greater than or equal to70 for Tl-Ba-Ca-Cu-O compounds and approx.15 for Bi-Sr-Ca-Cu-O compounds), as might be expected from highly oriented materials. The authors compare the preparation conditions and superconducting properties, including T/sub c/, ..delta..T/sub c/, dB/sub c2//dT (parallel and perpendicular to film surface), of all three compounds.

• Research Organization: 0448000
• OSTI ID: 6085678
• Report Number(s): CONF-880812-
• Conference Information: Journal Name: IEEE Trans. Magn.; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
420201* -- Engineering-- Cryogenic Equipment & Devices
656100 -- Condensed Matter Physics-- Superconductivity
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ANISOTROPY
ANNEALING
BARIUM COMPOUNDS
BARIUM OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUIPMENT
FABRICATION
FILMS
HEAT TREATMENTS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MAGNETIC FIELDS
MAGNETRONS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHYSICAL PROPERTIES
SPUTTERING
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
THALLIUM COMPOUNDS
THALLIUM OXIDES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES