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): US 5106829; A
• Application Number: PPN: US 7-587466
• OSTI ID: 5078086
• Resource Relation: Patent File Date: 19 Sep 1990
• Country of Publication: United States
• Language: English

Related Subjects

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