Fabrication of multifilament conductors: CVD processing of high-Tc superconducting composite fibers. Final Report, 14 May 1990 - 14 May 1992

Technical Report · Fri May 01 00:00:00 EDT 1992

OSTI ID:7229083

Kirlin, P S

The primary purpose of this project was to demonstrate the feasibility of Organo-Metallic Chemical Vapor Deposition (OMCVD) for production of BiSrCaCuO high-temperature superconductor coated wire. In order to carry out this objective, a low-pressure CVD reactor was designed with the capability to deposit continuously on a moving wire or fiber substrate. Substrate wire makes two passes through the reactor so that higher effective deposition rates can be achieved, leading to higher coated wire production rates. Ten to twenty foot lengths of superconductor precursor coated wire were produced in this way. Several significant obstacles were encountered and overcome during this project. Accumulating enough coated wire for analysis and fragility of the coatings, particularly before annealing, were both problems. Run-to-run reproducibility was also an issue. ATM's proprietary delivery system for low volatility source reactants worked quite well for Sr and Ca, but the Bi and Cu were delivered from bubblers, and the coatings showed substantial variations in these two elements from run to run. The main use of this specific work is a feasibility demonstration of low-pressure CVD on a continuously moving substrate with complex oxides. Coated wires several tens of feet in length were produced, with formation of the 2212 phase of BSCCO and a superconducting transition at 71 K. More generally, thin film coated wires have applications in superconducting magnets and power storage systems. Thin films have to date shown better flux pinning and thus J(sub c)S than bulk HTSC materials. Small filaments, i.e. wires, are preferred for winding magnets and dealing with alternating or rapidly changing currents, since they greatly reduce inductance losses.

• Research Organization: Advanced Technology Materials, Inc., Danbury, CT (United States)
• OSTI ID: 7229083
• Report Number(s): N-92-30711; NASA-CR-184344; NAS-1.26:184344; CNN: NAS8-38485
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH OXIDES
CHEMICAL VAPOR DEPOSITION
CALCIUM OXIDES
COPPER OXIDES
STRONTIUM OXIDES
SUPERCONDUCTING WIRES
FABRICATION
COATINGS
FEASIBILITY STUDIES
HIGH-TC SUPERCONDUCTORS
LOW PRESSURE
MAGNETIC FLUX
SUPERCONDUCTING MAGNETS
SUPERCONDUCTIVITY
THIN FILMS
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
COPPER COMPOUNDS
DEPOSITION
ELECTRIC CONDUCTIVITY
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTROMAGNETS
EQUIPMENT
FILMS
MAGNETS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRONTIUM COMPOUNDS
SUPERCONDUCTING DEVICES
SUPERCONDUCTORS
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
WIRES
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
665412 - Superconducting Devices- (1992-)