Sequentially evaporated thin Y-Ba-Cu-O superconductor films: Composition and processing effects

Conference · Wed Feb 01 04:00:00 EST 1989 · AIP Conference Proceedings (American Institute of Physics); (USA)

OSTI ID:7123047

Valco, G J; Rohrer, N J ^[1]; Warner, J D; Bhasin, K B ^[2]

---

1. Ohio State University, Columbus, Ohio 43210 (USA)
2. NASA Lewis Research Center, Cleveland, Ohio 44135 (USA)

Thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} have been grown by sequential evaporation of Cu, Y, and BaF{sub 2} on SrTiO{sub 3} and MgO substrates. The onset temperatures were as high as 93 K, while T{sub c} was 85 K. The Ba/Y ratio was varied from 1.9 to 4.0. The Cu/Y ratio was varied from 2.8 to 3.4. The films were then annealed at various times and temperatures. The times ranged from 15 min to 3 hours, while the annealing temperatures used ranged from 850 {degree}C to 900 {degree}C. There was found a good correlation between transition temperature (T{sub c}) and the annealing conditions; the films annealed at 900 {degree}C on SrTiO{sub 3} had the best T{sub c}'s. There was a weaker correlation between composition and T{sub c}. Barium poor films exhibited semiconducting normal state resistance behavior while barium rich films were metallic. The films were analyzed by resistance versus temperature measurements and scanning electron microscopy. The analysis is of the films and the correlations are reported.

• OSTI ID: 7123047
• Report Number(s): CONF-881035--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (USA) Journal Volume: 182:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
DEPOSITION
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
FILMS
HEAT TREATMENTS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCANNING ELECTRON MICROSCOPY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUBSTRATES
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
THICKNESS
THIN FILMS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES