Pulsed Laser Deposition of High T sub c Superconducting Thin Films
Abstract
Superconducting thin films have been deposited in-situ on several substrate materials using pulsed excimer laser deposition. On the standard oxide substrates, excellent films were obtained. They had high transition temperatures with narrow transition widths, metallic conductivity in the normal state, low room-temperature resistivity, high critical currents, c-axis orientation, and epitaxial alignment with the substrate. On the more technologically relevant substrates of sapphire and silicon, world record, though less optimal, results were obtained. The transition temperatures were high and metallic conductivity was obtained in the normal state. However, the room-temperature and microwave surface resistivities were higher and the critical currents lower than for the above substrates. These diminished transport properties correlate with the imperfect alignment and epitaxy of the superconductor substrate. For silicon substrates, a buffer layer is required due to high reactivity even at low temperatures. The best results were obtained on clean, hydrogen-terminated surfaces rather than oxidized silicon. Epitaxial alignment was achieved, but there was a substantial spread in orientations, accounting for the diminished transport properties. (RRH)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1989
- Accession Number
- ADA216507
Entities
People
- G. A. Connell
- J. B. Boyce
Organizations
- PARC