Microstructure YBCO Bulk Superconductors Fabricated by Infiltration Growth Process

Single grain YBCO bulk superconductors were prepared from different starting precursors. In the first case, Y2Ba1Cu1O5 (Y211) powder as the solid phase and the liquid phase of mixture of YBa2Cu3O7-x+BaCuO2+CuO powders were used. In the second case the solid phase was prepared from the mixture of Y2O3+BaCuO2 instead of the conventionally used Y211. The microstructure of samples was studied by polarized light microscopy and scanning electron microscope (SEM). The influence of different staring compositions on the final size of Y211 particles is shown. Also the influence of BaCuO2 concentration in the Y2O3+x·BaCuO2 (x=0.2; 0.5; 0.8; 1; 1.2; 1.5; 1.8) mixture on the Y211 size was studied.