LARGE DOMAIN GROWTH OF AG-DOPED YBACUO-SYSTEM SUPERCONDUCTOR

The effect of Ag addition on the phase diagram, solidification conditi ons and fabrication of large domain YBaCuO-system has been studied. Ca lcined powder of composition Y1.8Ba2.4Cu3.4O9-x with 0.5 wt.% Pt and 0 , 1, 5, 10, 20 and 30 wt.% Ag was prepared. The melting point of each powder was measured by differential thermal analysis (DTA). A large do main (45 mm diameter and 20 mm thick) of the Ag-doped YBaCuO-system su perconductor was prepared for each composition by a seeding and unidir ectional growth technique which involved controlling the furnace tempe rature gradient. In order to assess the quality of the crystal orienta tion, the distribution of trapped flux density was measured. The entir e sample was magnetized uniformly and the trapped magnetic field obser ved to form a single dome shape. (C) 1998 Elsevier Science S.A. All ri ghts reserved.