Properties of Bi2Sr2CaCu2O8 Thick Films Melt-Processed at Temperatures up to 950 C
Abstract
Thick Bi2Sr2CaCu208 films have been produced by melting Bi2Sr2CaCu208 Powder on MgO substrates at temperatures just above the melting temperature of the powder. X-ray diffraction measurements indicate enhanced c-axis alignment throughout the thickness of the films. Films melted at 900 deg. C show greater alignment and contain less Bi2Sr2Cu0 compared to those processed at 950 deg. C. Both the degree of alignment and the Bi2Sr2Cu06 content increase as the cooling rate is decreased. Transport measurements show that films quickly cooled from low melt-processing temperatures have the highest critical current densities (J (Sub c ) = 13 kA/Sq cm at 30 K). The temperature dependence of J (Sub c ) is best described by a flux creep model. Finally, J (Sub c ) at 4.2 K (in both parallel and perpendicular magnetic fields) undergoes a sudden drop at low fields, but levels off above 0.5 T to about 30% of the zero field value.... Superconductivity, Thin films, Transformer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1992
- Accession Number
- ADA266173
Entities
People
- J. S. Briggs
- W. C. Mcginnis
Organizations
- Naval Command, Control and Ocean Surveillance Center