Bi(Pb)SrCaCuO superconductors
AssigneeMerck Patent GmbH
InventorsRodney Riddle, Matthias Kuntz, Bernd Muller, Dietmar Raulin, Gunther Feldmann-Schlobohm
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Abstract
The invention relates to a spray pyrolytic process for the preparation of multi-element metal oxide powders useful as precursors of high temperature superconductor ceramics. Aerosols of aqueous solutions containing corresponding metal salts admixed in the required stoichiometric proportion are sprayed through an independently operated hydrogen/oxygen flame in such a way that a flame temperature of 800.degree.-1100.degree. C. is maintained to form said powders. Any contact of the aerosols and powders generated during the process with carbon or carbon-containing compounds or materials is strictly avoided.
Claims14
A high temperature superconductor ceramic formed from multi-element metal oxide powders having the formula Bi.sub.x Sr.sub.x Ca.sub.y Cu.sub.x O.sub.z, where x=1.0-3.0, y=0.5-2.5 and z is not specified or the formula Pb/Bi.sub.x Sr.sub.x Ca.sub.x Cu.sub.y O.sub.z, where x=1.5-3.0, y=2.5-3.5 and z is not specified, prepared by a spray-pyrolytic process comprising the steps of mixing salts of the metals needed to form said powders in an aqueous solution;
- forming an aerosol of said aqueous solution;
- spraying said aerosol through an independently operated hydrogen/oxygen flame having a temperature of 800.degree. C. to 1100.degree. C.;
- and collecting said powders which form after said spraying;
- wherein said aerosol and said powder do not contact elemental carbon, carbon containing compounds or materials containing carbon.
Dependencies are inferred from the claim text.