Accession Number : ADA326312

Title :   Thermal Boundary Resistance in a High Temperature Thin-Film Superconductor under Varying Heat Flux.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Magee, Michael P.

PDF Url : ADA326312

Report Date : DEC 1996

Pagination or Media Count : 87

Abstract : The thermal boundary resistance between a YBa2Cu3O7 thin film and an MgO substrate was measured under conditions of varying heat flux. Heat flux was varied in a manner to explore any hysteresis effects present. It was concluded that hysteresis effects are present and are most likely attributed to changes in the peeling or compressive stresses in the thin-film. The changes in the peeling stresses may not be fully relieved after cycling of the heat flux or may have caused microstructural changes near the interface resulting in changes in microscale heat transfer characteristics. Additionally, finite difference method were used to model the physical situation. It was found that boundary resistance values generated by the computer program were several orders of magnitude less than experimental value. It was concluded that finer meshes must be used in order to increase the accuracy of the results. It was recommended that the modeling be redone on a main frame computer using finite element methods.

Descriptors :   *HEAT TRANSFER, *HIGH TEMPERATURE SUPERCONDUCTORS, COMPUTER PROGRAMS, MICROSTRUCTURE, FINITE ELEMENT ANALYSIS, THIN FILMS, THESES, SUBSTRATES, FINITE DIFFERENCE THEORY, HEAT FLUX, THERMAL BOUNDARY LAYER, HYSTERESIS, COPPER OXIDES, THERMAL RESISTANCE, COMPRESSIVE PROPERTIES.

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE