The discovery of superconducting oxides with a critical temperature above the boiling point of nitrogen has led to an enormous scientific and practical interest over the last decade. As a consequence, numerous approaches have been tried to synthesize products as pure as possible with optimal morphology and physical properties [1]. The most conventional method is the 'ceramic' technique [2], which involves mixing, grinding and heating of powders of metal oxides and carbonates. This technique requires multiple grindings and prolonged thermal treatment at high temepratures to achieve complete reaction since the formation of the superconducting phase proceeds via diffusion in the solid state. To achieve better mixing of the initial products, many chemical preparation techniques [3] for precursors have been developed (coprecipitation-filtration [4,5], sol-gel [6,7], spray-drying [8]) in which the reagents are mixed at a molecular level in solution and should therefore lead to more homogeneous end products that can be prepared at lower temperatures and/or in shorter times. Moreover, chemical precursors tend to be more suitable for making various shapes such as films, fibres, wires...
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