Synthesis of YBa₂Cu₃O_7−x powder by autoignition of citrate-nitrate gel

A simple and convenient method for the synthesis of YBa₂Cu₃O_7−x powder is described. The technique involves autoignition of a citrate-nitrate gel resulting from a thermally induced oxidation-reduction reaction to yield an ash that upon calcination produces the desired compound. The resulting powder is pure, homogeneous, and possesses a reasonably fine particle size. The autoignition is restricted to a particular range of citrate-nitrate ratio in the gel. Attempts have been made to understand the ignition process with the help of Thermogravimetry (TG) and Differential Thermal Analysis (DTA) of the samples. The process appears to have a higher degree of reproducibility and a good potential for large-scale production.