Fabrication of oxide superconductors by melt growth method

Patent · Tue Apr 30 04:00:00 EDT 1991

OSTI ID:5097728

Jin, S; Sherwood, R C; Tiefel, T H

This paper describes a method of fabricating a body that comprises a superconductive oxide of nominal composition Ba{sub 2{minus}z}M{sub 1{minus}y}X{sub x + y}Cu{sub 3}O{sub 7+{delta}} where M is selected from the group consisting of Y Eu, La, and combinations thereof, the optional X is different from Ba and M and is selected from the group consisting of the elements of atomic number 57-71, Sc, Ca and Sr, with 0 {le} x + y {le} 1 and 0 {le} {delta} {le} 0.5, and with Ba and M being at least 50% unsubstituted. It comprises: providing a quantity of precursor material comprising an oxide of one or more of Ba, Cu, M and X, associated with the precursor material is a phase diagram comprising a solid-liquid region and a liquid regions, and a solidus temperature; heating the precursor material such that at least a portion thereof is at a temperature above the solidus temperature and is a liquid; cooling at least a part of the liquid precursor material to a temperature below the solidus temperature such that re-solidified precursor material results, the rate of cooling selected such that at least a substantial portion of the re-solidified precursor material comprise elongate grains, associated with a given elongate grain being a long axis and an aspect ratio, at least a substantial fraction of the elongate grains measuring at least about 10 {mu}m along the long axis and having an aspect ratio of at least 10:1: and heat treating the re-solidified precursor material in an oxygen-containing atmosphere such that the superconductive oxide is produced from the re-solidified precursor material.

• Assignee: AT and T Bell Lab., Murray Hill, NJ (USA)
• Patent Number(s): US 5011823; A
• Application Number: PPN: US 7-126083
• OSTI ID: 5097728
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
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