Method for preparation of textured YBa.sub.2 Cu.sub.3 O.sub.x superconductor
AssigneeLockheed Martin Energy Systems, Inc.
InventorsVenkat Selvamanickam, Amit Goyal, Donald M. Kroeger
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Abstract
The present invention relate to textured YBa.sub.2 Cu.sub.3 O.sub.x (Y-123) superconductors and a process of preparing them by directional recrystallization of compacts fabricated from quenched YBCO powders at temperatures about 100.degree. C. below the peritectic temperature to provide a superconductor where more than 75% of the YBa.sub.2 Cu.sub.3 O.sub.x phase is obtained without any Y.sub.2 BaCuO.sub.5 .
Claims19
A process for producing a YBCO superconductor without forming a Y-211 precursor phase comprising:
- heat-treating yttrium rich precursor powders at a temperature of about 1400.degree. C., rapidly cooling the heat-treated material, pelletizing the cooled material to form yttrium rich YBCO powders, and subsequently
- directionally recrystallizing the heat-treated yttrium rich YBCO powders at a temperature of about 100.degree. below the peritectic temperature to form a superconductor with more than 75% of a YBa.sub.2 Cu.sub.3 O.sub.x phase free from Y.sub.2 BaCuO.sub.5.
A process for producing a YBCO superconductor comprising:
- a) heating calcined yttrium rich YBCO powders at about 1400.degree. C.;
- b) splat quenching the heated powder;
- c) crushing the quenched powder;
- and
- d) directionally recrystallizing the crushed powder at a temperature of about 100.degree. below the peritectic temperature to form a superconductor with more than 75% of a YBa.sub.2 Cu.sub.3 O.sub.x phase free from a Y.sub.2 Ba.sub.2 CuO.sub.5, whereby the formation of a Y-211 precursor phase is avoided.
A process of producing a YCBO 123 superconductor comprising:
- a) providing and heating an yttrium rich YBCO composition at a temperature of about 1400.degree. C. to restrict the formation of Ba- and Cu-rich phases in the final material and to supersaturate the liquid phase at 1400.degree. C. with yttrium;
- b) rapidly quenching the heated material of step a);
- and
- c) directionally recrystallizing the product of step b) at a temperature of about 100.degree. below the peritectic to form a textured YBCO 123 superconductor.
Dependencies are inferred from the claim text.