Microstructure and superconducting properties of melt textured Y-Ba-Cu-(Ag)-O composites with various Ag content

The effects of silver doping on microstructure and magnetic properties of YBa2Cu3O7-x melt-textured samples prepared by the quench and melt growth technique were studied. Silver was added in the form of Ag2O in the range of 0-10 wt%. The increasing silver doping level up to the level of 1.0 wt% Ag2O of YBa2Cu3O7-x samples results in remarkable improving of their magnetic properties, texturation and porosity. For the given processing conditions, the superconducting properties strongly decrease for the higher doping levels of 5.0 wt% Ag2O and more. In our case in reaction systems with higher content of silver doping, which remarkably depresses the formation temperature of the superconductor phase, the texturation process was not completed. The best developed texture as well as the highest magnetisation and first, penetration magnetic field showed, under our experimental conditions, the sample containing 1 wt% Ag2O. (C) 2001 Elsevier Science Ltd. All rights reserved.