Thermal treatment of a Y-123 precursor prepared using the hydroxide co-precipitation method

A Y-123 precursor has been obtained using the hydroxide co-precipitation me thod. The influences of the calcination time and temperature (with and with out sintering and annealing) on the formation of the superconducting phase, YBa2Cu3O7-delta, are examined using XRD and T-c measurements. A comparison between the co-precipitated hydroxide precursor and the conventional dry p recursor, obtained by mixing oxides acid carbonates, is made. It shows that thermal treatment of the hydroxide precursor at 750 degrees C already give s a superconductor, while the oxide-carbonate precursor is only superconduc ting after thermal treatment at 850 degrees C. (C) 1999 Elsevier Science Lt d. All rights reserved.