Laser zone melted Bi--Sr--Ca--Cu--O thick films
US5015618A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1989 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Oct 19, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/729
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for preparing a highly aligned thick film of superconducting bismuth strontium calcium copper oxide ceramic material to improve its critical current density. A film about 5-200 .mu.m thick of bismuth strontium calcium copper oxide is deposited on a suitable substrate. The ratios of Bi:(Sr, Ca):Cu in the film are about 2:3:2 to 2:4:3. A laser beam is translated over the deposited film at a rate of about 0.2-15 cm/hr while the film is held at a temperature of about 500.degree.-950.degree. C. The beam is about 0.01-0.50 cm wide along the direction of translation, and provides about 0.2-10W of optical power to the film. The temperature and the beam translation rate, width, and optical power are selected to permit zone melting and resolidification of the film to form the highly aligned thick film of superconducting bismuth strontium calcium copper oxide ceramic material. The J.sub.c may, if desired, be further improved by annealing the resolidified film at about 900.degree.-965.degree. C. for about 1-300 hr.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.