Method for making high-critical-current-density YBa.sub.2 Cu.sub.3 O.sub.7 superconducting layers on metallic substrates
AssigneeLockheed Martin Energy, LLC
InventorsRoeland Feenstra, David Christen, Mariappan Paranthaman
Life of this patent
Estimating the term…
Abstract
A method is disclosed for fabricating YBa.sub.2 Cu.sub.3 O.sub.7 superconductor layers with the capability of carrying large superconducting currents on a metallic tape (substrate) supplied with a biaxially textured oxide buffer layer. The method represents a simplification of previously established techniques and provides processing requirements compatible with scale-up to long wire (tape) lengths and high processing speeds. This simplification has been realized by employing the BaF.sub.2 method to grow a YBa.sub.2 Cu.sub.3 O.sub.7 film on a metallic substrate having a biaxially textured oxide buffer layer.
Claims2
A method for preparing a high critical current density ReBa.sub.2 Cu.sub.3 O.sub.7 superconducting layer on a metallic substrate, wherein Re denotes a rare earth metal, comprising the steps of:
- (a) providing the metallic substrate, said substrate having a biaxially textured buffer layer;
- (b) depositing a precursor film on the buffer layer by delivering Cu, BaF.sub.2, and at least one of the group consisting of:
- Y;
- and a rare earth metal selected from the La-series, onto the buffer layer;
- (c) annealing the precursor film to form a superconducting ReBa.sub.2 Cu.sub.3 O.sub.7 structure by heating the film to a sufficient temperature in the presence of a suitable gas mixture for a sufficient time to allow formation of the superconducting ReBa.sub.2 Cu.sub.3 O.sub.7 structure;
- and
- (d) heating the film of step c in oxygen to a sufficient temperature and for a sufficient time to increase the oxygen concentration in the ReBa.sub.2 Cu.sub.3 O.sub.7 structure so that said ReBa.sub.2 Cu.sub.3 O.sub.7 structure is characterized by a critical current density of at least 100,000 A/cm.sup.2 at 77 K and OT.
Dependencies are inferred from the claim text.