Method of making substantially single phase superconducting oxide ceramics having a T sub c above 85 degrees

Patent · Tue Apr 21 00:00:00 EDT 1992

OSTI ID:5078086

Quadri, S B; Toth, L E; Osoksky, M S; Lawrence, S H; Gubser, D U; Wolf, S A

This patent describes a method for producing a substantially single phase superconducting ceramic composition having a T{sub c} above 85K. It comprises mixing stoichiometric quantities of fine particle size powders of a superconducting rare earth oxide, barium carbonate and copper oxide to form an evenly dispersed mixture; calcining the mixture at a predetermined temperature of about 900{degrees} C to about 950{degrees} C in an oxygen-containing environment for a period sufficient to calcine substantially the entire mixture; maintaining a fine particle size for the mixture during and subsequent to calcination; forming the fine particle size calcined mixture into a shape substantially free of voids; sintering the shape in an oxygen-containing environment at a predetermined temperature of about 900{degrees} C to about 950{degrees} C for a period of time sufficient to substantially densify the shape; cooling the shape over a period of about 2 to 24 hours in an oxygen-containing environment at a rate which is sufficiently slow to form a substantially single phase superconducting composition having an orthorhombic crystal lattice and a T{sub c} greater than 85K.

• Assignee: Secretary of the Navy, Washington, DC (United States)
• Patent Number(s): A; US 5106829
• Application Number: PPN: US 7-587466
• OSTI ID: 5078086
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360207 -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
665411 -- Basic Superconductivity Studies-- (1992-)
665412* -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
COPPER COMPOUNDS
COPPER OXIDES
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FABRICATION
HIGH-TC SUPERCONDUCTORS
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SIZE
STOICHIOMETRY
SUPERCONDUCTIVITY
SUPERCONDUCTORS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS