Tl-Ca-Ba-Cu-O compositions electrically superconducting above 120 degree K and processes for their preparation
AssigneeInternational Business Machines Corporation
InventorsEdward M. Engler, Victor Y. Lee, Adel I. Nazzal, Stuart S. P. Parkin
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Abstract
Stable, bulk electrical superconductors are prepared by heating mixed metal oxides in the presence of oxygen in a closed vessel in a preheated oven for 1-5 hours at 850.degree.-900.degree. C. The final oxides are in the molar ratio Tol.sub.0.6-1.1 Ca.sub.2-3 Ba.sub.0.75-1.25 Cu.sub.2-3 O.sub.(5+.delta.)-(9+.delta.), where .delta. is less than one.
Claims3
A stable, bulk electrical superconductor with zero resistance above 120.degree. K. confirmed with magnetic susceptibility measurements, having a composition in the range Tl.sub.0.6-1.1 Ca.sub.2-3 Ba.sub.0.75-1.25 Cu.sub.2-3 O.sub.(5+.delta.)-(9+.delta.), where .delta. is less than one.
Dependencies are inferred from the claim text.