Abstract: A novel process of the production and processing of high quality, high Tc (Bi,Pb)SCCO superconductors starts with fabrication of a precursor article including selected intermediate phases with desired chemical and structural properties. The precursor fabrication includes introducing the reacted mixture having a dominant amount of the tetragonal BSCCO phase into a metal sheath, and sealing the reacted mixture within said sheath, heating the mixture at a second selected processing temperature in an inert atmosphere with a second selected oxygen partial pressure for a second selected time period, the second processing temperature and the second oxygen partial pressure being cooperatively selected to form a dominant amount of an orthorhombic BSCCO phase in the reacted mixture.
Type:
Application
Filed:
October 25, 2001
Publication date:
August 15, 2002
Inventors:
Qi Li, Eric R. Podtburg, Patrick John Walsh, William L. Carter, Gilbert N. Riley, Martin W. Rupich, Elliott Thompson, Alexander Otto
Abstract: A new boron-carbon system superconductive substance has a nominal composition expressed R.sub.3 M.sub.4-x B.sub.4-y C.sub.3-z (where R is at least one element selected from the group consisting of Y, Sc and lanthanide series elements, M is at least one metal element categorized in VIII group of periodic table, and 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.z<3, except a case of x=y=1 and z=0).
Abstract: An oxide superconductor comprises a composition represented by the composition formula: (Nd.sub.x --Ce.sub.y --L.sub.z).sub.2 CuO.sub.4-d (wherein L is an element selected from Ca and Mg, and x+y+z=1). The compositions of Nd, Ce and L of the oxide superconductor corresponds to a point falling inside an area of Nd--Ce--L ternary diagram surrounded by straight lines (A-B), (B-C), (C-D) and (D-A) connecting point (A) with point (B), point (B) with point (C), point (C) with point (D) and point (D) with point (A), respectively, the points (A), (B), (C) and (D) being points (x=1, y=0, z=0), (x=0.4, y=0.6, z=0), (x=0.4, y=0.3, z=0.3) and (x=0.1, y=0, z=0.9), respectively, in the Nd--Ce--L ternary diagram. Above-described Nd--Ce--L--Cu--O oxides can exhibit superconductivity within a wide range of composition when heat-treated in an atmosphere of nitrogen.
Type:
Grant
Filed:
October 9, 1991
Date of Patent:
September 14, 1993
Assignees:
Mitsubishi Metal Corporation, Hitachi, Ltd., International Superconductivity Technology Center
Abstract: A silver coated superconducting ceramic powder made by(1) coating the superconducting ceramic powder particles with AgNO.sub.3 ;(2) melting the AgNO.sub.3 so that it wets and forms a uniform coating over the surfaces of the particles; and(3) decomposing the AgNO.sub.3 to form a thin, uniform coating of silver metal on the surfaces of the particles.The product is a loose powder of superconducting ceramic particels which are uniformly coated with a thin layer of silver metal. The powder can be cold worked (e.g., swaged, forged, etc.) to form superconducting structures such as rods or wires.
Type:
Grant
Filed:
August 2, 1990
Date of Patent:
January 21, 1992
Assignee:
The United States of America as represented by the Secretary of the Navy
Abstract: A superconductive material with a superconducting critical temperature of at least 77.degree. K. comprising 20 at. % Nb, 10 at. % Si, 10 at. % Al and 60 at. % O is provided by simultaneous vapor-phase physical deposition or sputtering of Nb, Si and Al onto a heated sapphire substrate under oxygen-containing atmosphere, followed by a rapid quenching or post-oxidization of Nb-Si-Al ternary system composition having an Nb/Si/Al atomic ratio of 2/1/1. The high critical temperature allows abundantly existing, cheap available liquid nitrogen to be used as a cryogen for developing superconductivity.
Abstract: Copper alkoxy alkoxides of the formula CuOR or Cu(OR).sub.2, where R is derived from an alkoxy alkanol of from 3 to 8 carbon atoms, are superconducting ceramic precursors. Compositions containing these alkoxides solubilized in an organic solvent, such as toluene, can be prepared by the additional use of a barium alkoxide solubilization agent.
Type:
Grant
Filed:
December 7, 1987
Date of Patent:
July 11, 1989
Assignee:
Texas Alkyls, Inc.
Inventors:
Andrzej M. Piotrowski, Dennis B. Malpass
Abstract: Metal oxide superconductors of the yttrium-barium-copper type (YBa.sub.2 Cu.sub.3 O.sub.4 type) can be formed by precipitation from an aqueous solution of the salts of the metals using an oxalate precipitation reagent under basic pH conditions (e.g., at least 11) to form a fireable precursor only partly in the form of the oxalate salts of these metals.