Mercury-thallium-barium-calcium-strontium-copper-oxide 1223 superconductor and method of making same
AssigneeKorea Research Institute of Standards and Science
InventorsYong H. Hur, Yong K. Park, Jong C. Park
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Abstract
Mercury-thallium based superconductors with the formula Hg.sub.1-x Tl.sub.x Ba.sub.2 (Ca.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.8+.delta. ; change "their preparing method, in particular characterized in that it" to and a method for preparing them. The new superconductors are prepared by reacting respective ternary oxides, such as Ba.sub.2 CuO.sub.3+x and Ca.sub.1-y Sr.sub.y CuO.sub.2, to reduce the formation of an impure phase and by substituting thallium (Ti) a portion of the mercury (Hg) conventionally used in mercury-based superconductors of similar structure, in order to thermally stabilize the superconductor and provide it with a high critical current density characteristic.
Claims2
A mercury-thallium-based superconductor with the formula:
- Hg.sub.1-x Tl.sub.x Ba.sub.2 (Ca.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.8+.delta.
- wherein x is from about 0.25 to about 0.75and y is greater than 0.1 and less than 0.2.
A method of preparing a mercury-thallium-based superconductor with the formula:
- Hg.sub.1-x Tl.sub.x Ba.sub.2 (Ca.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.8+.delta.
- wherein x is from about 0.25 to about 0.75 and y is greater than 0.1 and less than 0.2, said method comprising the steps of:
- mixing HgO, Tl.sub.2 O.sub.3, Ba.sub.2 CuO.sub.3+x and Ca.sub.1-y Sr.sub.y CuO.sub.2 in powder form;
- pressing the resulting powder mixture into pellets;
- placing said pellets in an alumina tube;
- putting said alumina tube containing said pellets into a quartz tube;
- sealing said quartz tube to create an ampule;
- sintering said pellets in said ampule at 860.degree..about.880.degree. C.;
- and
- annealing the resulting sintered pellets at 300.degree..about.400.degree. C. in an argon atmosphere.
Dependencies are inferred from the claim text.