YBa2Cu3O7-x superconductor using a sol/gel approach

This paper reports a powder of the YBa2Cu3O7-x ceramic superconductor using an ethylene glycol and citric acid approach. The sol was gelled by heating and then calcined to form the powder. Our approach produced a foamed gel where the powder is less agglomerated than powders prepared without foaming. This powder was found by X-ray diffraction to be a phase pure orthorhombic YBa2Cu3O7-x. Sintered samples had a density of 94% after 3 hours at 93 degrees C in a flowing oxygen atmosphere and had superconducting transitions starting at 93 degrees K with a 1-2 degree K transition width to the superconducting state. Dilatometer results on the sintering of the powder are presented as well as scanning electron micrographs on powder morphology and sample microstructure