Metal Nitrate-Urea Decomposition Route for Y-Ba-Cu-O Powder

Y-Ba-Cu-O powder, having desirable composition, particle size, compaction, and sintering properties, has been prepared by a novel combustion process involving metal nitrate-urea decomposition. Single-phase Y-Ba-Cu-O is obtained by reacting the mixture of yttrium, barium, and copper nitrates in 123 stoichiometry with urea at 900°C for a period of 1 h. Following grinding in acetone the powder possessed an average particle size of 1 μm, a surface area of 42.2 m²/g, a bulk density of 2.7 g/cm³, and could be sintered to 92% theoretical density at 930°C with the resulting material having a T _c of 90 K.