Method for in-situ prevention of stable barium carbonate formation in high T[sub c] ceramic superconductor including the use of iodine or an iodine c

Patent · Tue Oct 06 00:00:00 EDT 1992

OSTI ID:6965352

Chen, K C; Mazdiyasni, K S

This patent describes a method of making a pre-ceramic resinous material capable of being converted into a ceramic semiconductor material substantially free from stable barium carbonate and having the general composition RR[prime][sub 2]Cu[sub 3]O[sub 7[minus]x] where R is a rare earth metal, R[prime] is an alkaline earth metal, and x is from 0 to 0.5. It comprises: refluxing stoichiometric amounts of a first solution comprising a rare earth isopropoxide and an alkaline earth isopropoxide in isopropanol; adding to the first solution a stoichiometric amount of a second solution comprising copper ethylhexanoate in isopropanol; refluxing the first and second solutions to obtain a precipitate; hydrolyzing the precipitate in a quantity of a first solvent comprising water and isopropanol sufficient to substantially dissolve the precipitate into a precipitate solution; adding a third solution comprising an iodine compound in an alcohol to the precipitate solution to form a precursor solution having at least about 1 mole of iodine per mole of rare earth metal; concentrating the precursor solution by removing a sufficient amount of solvents to produce the pre-ceramic resinous material; and adding a second solvent comprising a nonpolar solvent to the pre-ceramic resinous material to obtain a desired viscosity.

• Assignee: General Atomics, San Diego, CA (United States)
• Patent Number(s): US 5153172; A
• Application Number: PPN: US 7-591440
• OSTI ID: 6965352
• Resource Relation: Patent File Date: 1 Oct 1990
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKALINE EARTH METAL COMPOUNDS
SUPERCONDUCTIVITY
CUPRATES
HIGH-TC SUPERCONDUCTORS
CHEMICAL PREPARATION
RARE EARTH COMPOUNDS
CHEMICAL COMPOSITION
PHASE STABILITY
SOLUTIONS
STOICHIOMETRY
VISCOSITY
COPPER COMPOUNDS
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MIXTURES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STABILITY
SUPERCONDUCTORS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
665412* - Superconducting Devices- (1992-)
360207 - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies
400201 - Chemical & Physicochemical Properties