Method of producing YBa sub 2 Cu sub 3 O sub 6+x superconductors with high transition temperatures

Patent · Tue Jan 08 00:00:00 EST 1991

OSTI ID:5749600

Rao, A S; Arora, O P; Aprigliano, L F

This patent describes a method for making an improved ceramic superconductor. It comprises: mixing an oxide selected from the group consisting of Y{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Eu{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, Dy{sub 2}O{sub 3} and Ho{sub 2}O{sub 3} with barium carbonate and copper oxide powders in a ratio of about 50 grams in the case of Y{sub 2}O{sub 3}, 83 grams for Er{sub 2}O{sub 3}, 76 grams for Eu{sub 2}O{sub 3}, 86 grams of Ho{sub 2}O{sub 3} to about 70 grams of BaCO{sub 3} to about 105 grams of CuO, ball milling the mixture with zironia balls for at least on hour; calcining the mixture at a temperature of 940{degree}C + or {minus}{degree} C with a heating sequence of 2{degree}C per minute from room temperature to 200{degree}C, maintaining the mixture at the 200{degree} C temperature for a least about sixty minutes, heating the mixture at 3{degree} C per minute until a temperature of 940{degree} C + or {minus}2{degree} C is reached, maintaining the mixture at the 940{degree} C + or {minus}2{degree} C for three hundred minutes, cooling the mixture to room temperature at a rate of 1{degree}C per minute, adding silver oxide in powdered form to the mixture an amount of from about 1 to about 20 weight percent, ball milling the mixture containing silver oxide for at least one hour, compacting the mixture, sintering the mixture at 920{degree} C + or {minus}2{degree} C by heating the mixture at 2{degree} C per minute from room temperature 200{degree} C, maintaining the temperature at 200{degree} C for 60 minutes and then resuming the heating at 3{degree} C per minute until a temperature of 920{degree} C is reached, (l) maintaining the mixture at 920{degree} C + or {minus}2{degree} C for three hundred minutes, and (m) cooling the mixture to room temperature at a rate of {degree} C per minute.

• Assignee: Secretary of the Navy, Washington, DC (USA)
• Patent Number(s): US 4983571; A
• Application Number: PPN: US 7-472008
• OSTI ID: 5749600
• Resource Relation: Patent File Date: 30 Jan 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DYSPROSIUM OXIDES
SYNTHESIS
ERBIUM OXIDES
EUROPIUM OXIDES
HOLMIUM OXIDES
YTTERBIUM OXIDES
YTTRIUM OXIDES
CERAMICS
SUPERCONDUCTORS
CHALCOGENIDES
DYSPROSIUM COMPOUNDS
ERBIUM COMPOUNDS
EUROPIUM COMPOUNDS
HOLMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTERBIUM COMPOUNDS
YTTRIUM COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication