COMBUSTION SYNTHESIS OF YBA2CU3O7-X GLYCINE METAL NITRATE METHOD

A combustion synthesis method has been developed to simply and rapidly prepare YBa2Cu3O7-x and YBa2Cu3O7-x/Ag from an aqueous solution of the metal nitrates and glycine. Glycine served both as the fuel for combustion and as a complexant, important to prevent inhomogeneous precipitation of individual components prior to combustion. Ash collected following combustion consisted of well-mixed, soft agglomerates of barium carbonate, yttrium oxide, cupric oxide, and/or copper metal, depending on the ratio of fuel to oxidant. This mixture was calcined at 900-degrees-C for 4 h to convert the product to YBa2Cu3O7-x. Samples sintered at 950-degrees-C for 8 h and annealed in oxygen at 450-degrees-C for a like time showed a T(c) (midpoint) of 92.5 K with a width of 1.4 K and a high degree of phase-purity. This synthesis method is well suited to the preparation of a wide variety of multicomponent ceramics.