TRANSPORT-PROPERTIES OF SB2O3 DOPED LASER-ABLATED YBA2CU3O7-DELTA

The effect of Sb2O3 addition on YBa2Cu3O7-alpha films grown on [100] L aAlO3 by pulsed laser ablation has been studied. Transport measurement showed that though the critical temperature T(c) is slightly suppress ed upon Sb2O3 doping, the critical current density J(c) increases up t o 2.5 x 10(6) A cm-2 at 77 K for the critical concentration of 0.5 wt. % Sb2O3 and then decreases monotonically for further increase in Sb2O3 content. The increase in J(c) with 0.5 wt.% Sb2O3 addition is presume d to be due to the surfactant effect of Sb2O3 and the decrease in J(c) with the further increase of Sb2O3 content has been attributed to the formation of secondary insulating phase YBa2SbO6 as found by X-ray di ffraction.