SYNTHESIS AND PROPERTIES OF YBA2CU3O7-DELTA MADE BY A MODIFIED HYDROXYCARBONATE METHOD

YBa2Cu3O7-delta was synthesised using a solution method, The coprecipi tation of the stoichiometric amounts of nitrate solution of yttrium, b arium and copper was performed using a mixture of NaOH, Na2CO3 and H2C 2O4 in a molar ratio 5:1:1 as precipitation agent. The as-obtained pre cursors have a copper deficiency of 0.1 with respect to the nominal st oichiometry of the starting solution, The mechanistic study of the pro duct formation has revealed that in these atomically mixed precursors the individual components have a different behaviour with respect to t hose in a mechanical mixture. The final products was obtained after he at treatment at 950 degrees C for 6 h in oxygen atmosphere, The produc t was analyzed by XRD, SEM, EDXS and four probe DC resistivity measure ments, The as-synthesised YBCO has shown good superconducting properti es T-c(R = 0) = 90.5 K and Delta T = 1 K, This method was used with su ccess in the fabrication of YBCO laser ablation.