Sol-gel synthesis of YBa2Cu3O7-x superconductor by mixed organic-inorganic polymerization
Creators
- 1. Laboratoire de Spectrochimie du Solide, 75 - Paris (France)
Description
Sol-gel processes are quite attractive methods to produce films or fibers of high Tc superconducting materials. The gel step allows a good chemical homogeneity and generally provides a rather low processing temperature. Blue sols or monolithic gels can be easily produced using mixed organic-inorganic polymerisation of molecular precursors. An aqueous solution of copper, barium acetates and yttrium nitrate is mixed with an acrylic acid solution where a radical organic polymerisation process has been initiated. After pH adjustments, the viscosity of the resulting solution can be adjusted by heating. After drying at 1500C and calcination above 7000C, the YBaCuO network is formed and superconducting properties appears above 8500C. Fine particles (0.1-1 μm) are obtained which can be sintered to produce a ceramic material with a particularly narrow resistive transition
Abstract (French)
La synthese de sols ou de gels precurseurs d'oxydes est a la base de tout procede visant a produire des films ou des fibres de materiaux supraconducteurs a haute temperature critique. L'etape gel assure une bonne homogeneite chimique et l'elaboration a une temperature relativement basse. Nous avons ainsi reussi a obtenir des sols ou des gels bleus monolithiques par polymerisation mixte organique-inorganique de precurseurs mineraux. A une solution de sels de cuivre, baryum et yttrium est ajoutee une solution d'acide acrylique ou la polymerisation organique radicalaire a ete amorcee. Le pH de la solutions est ajuste a 7. La viscosite d'une telle solution peut ensuite etre ajustee par simple chauffage. On passe alors d'une solution colloidale a un gel puis a un xerogel en chauffant respectivement a 800C et 1500C. Apres calcination a 7000C, on forme le reseau YBaCuO dont les proprietes supraconductrices apparaissent a partir de 8500C. Les particules fines (entre 0,1 et 1μm) peuvent etre frittees pour donner une ceramique ayant une transition resistive nette et etroite semblant indiquer de tres bons contacts entre les grainsAdditional details
Additional titles
- Original title (French)
- Synthese sol-gel d'un supraconducteur YBa
Publishing Information
- Journal Title
- Industrie Ceramique
- Journal Issue
- no.836
- Series
- Ind. Ceram.
- ISSN
- 0019-9044
- CODEN
- IDCQA
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 20075469
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- BARIUM OXIDES; COPPER OXIDES; GELS; POLYMERIZATION; SOLS; SUPERCONDUCTIVITY; SYNTHESIS; TYPE-II SUPERCONDUCTORS; YTTRIUM OXIDES
- Descriptors DEC
- ALKALINE EARTH METAL COMPOUNDS; BARIUM COMPOUNDS; CHALCOGENIDES; CHEMICAL REACTIONS; COLLOIDS; COPPER COMPOUNDS; DISPERSIONS; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SUPERCONDUCTORS; TRANSITION ELEMENT COMPOUNDS; YTTRIUM COMPOUNDS