Method of making Tl-Sr-Ca-Cu-oxide superconductors comprising heating at elevated pressures in a sealed container
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsWilliam L. Lechter, Michael S. Osofsky, Earl F. Skelton, Louis E. Toth
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Abstract
High T.sub.c superconducting compounds are made by forming a reaction mixture of the oxides of Sr, Cu, Ca and Tl, compressing these into a hardened body, and placing the hardened body into a container. The container is then evacuated and sealed. The hardened body is heated under pressure until the oxides of Sr, Ca, Cu, and Tl react to form a superconducting compound.
Claims18
A method of forming a Tl-Sr-Ca-Cu-oxide high T.sub.c superconductor comprising the steps of:
- forming a reaction mixture of the oxides of Sr, Cu, Ca, and Tl in stoichiometric proportions to make a Tl-Sr-Ca-Cu-oxide high T.sub.c superconducting compound;
- compressing the reaction mixture into a hard body;
- placing the hard body into a container for containing thallium vapor;
- evacuating and sealing the hard body in the container;
- heating the hard body and the container at a temperature of about 800.degree. C. to about 950.degree. C. and under pressure of at least about 30,000 psi until said container metal around said hard body and the oxides of Tl, Sr, Ca, and Cu react to form a superconducting compound;
- and
- cooling the superconducting compound to room temperature and returning the superconducting compound to atmospheric pressure.
A method of forming a Tl-Sr-Ca-Cu-oxide high T.sub.c superconductor comprising the steps of:
- forming a powdered mixture of SrCO.sub.3, CuO, CaCO.sub.3 ;
- converting the carbonates in the powdered mixture to oxides, forming an oxide mixture;
- forming a reaction mixture of the oxide mixture and Tl.sub.2 O.sub.3 in stoichiometric proportions to make a Tl-Sr-Ca-Cu-oxide high T.sub.c superconducting compound;
- compressing the reaction mixture into a hard body;
- placing the hard body into a container;
- evacuating and sealing the hard body in the container;
- heating the hard body and the container under pressure until said container melts around said hard body and the oxides of Tl, Sr, Ca, and Cu react to form a superconducting compound;
- and
- cooling the superconducting compound to room temperature and returning the superconducting compound to atmospheric pressure.
Dependencies are inferred from the claim text.