Environmental Degradation of High Tc Superconductors
The recent discovery of high temperature ceramic superconductors sparked off tremendous research efforts all over the world and brought along promises of wide spread use in magnetically levitated trains and ultrafast computers. Prior to 1986, superconductors had to be cooled to liquid helium temperature (4 Kelvin), but recently isolated cases of transition temperatures (Tc) as high as 240 Kelvin have been reported for the newly discovered ceramic compounds. Thin films of high Tc superconductors have promising applications in semiconductor and microelectronics industry since they have high critical current density (Jc)· They also lend themselves to the study of materials parameters responsible for superconduction. However, an inherent problem with high Tc superconducting material is its rapid degradation upon exposure to moisture and water and the subsequent breakdown of superconductivity. In an effort to characterize the degradation pattern of superconductors, a series of controlled tests were run in an in-house fabricated humidity chamber. Bulk material and RF sputter deposited thin films on various substrates were exposed to desired levels of relative humidity for various lengths of time. Comparative studies of the surface and bulk characteristics were performed before and after exposure using i) magnetic susceptibility, ii) Tc measurements, iii) scanning Auger microscopy, iv) x-ray diffraction, v) scanning electron microscopy, vi) energy dispersive x-ray spectroscopy, and vii) optical microscopy. Each one of these techniques provided information on certain aspects of the corrosion phenomena of superconductors and a correlation between the data was used for comprehensive understanding of the degradation process.
This item is only available in print in the UCF Libraries. If this is your thesis or dissertation, you can help us make it available online for use by researchers around the world by downloading and filling out the Internet Distribution Consent Agreement. You may also contact the project coordinator Kerri Bottorff for more information.
Desai, Vimal H.
Master of Science (M.S.)
College of Engineering
Mechanical Engineering and Aerospace Sciences
Length of Campus-only Access
Masters Thesis (Open Access)
Dissertations, Academic -- Engineering; Engineering -- Dissertations, Academic
Arora, Sumesh Mohan, "Environmental Degradation of High Tc Superconductors" (1990). Retrospective Theses and Dissertations. 3950.