Superior growth orientation control via ZnO doping of large-grain LRE-Ba_2Cu_3O_Y compounds grown with MgO seeds

摘要

MgO seeds proved to be efficient in the growth orientation control of large grain LREBa_2Cu_3O_y 'LRE-123' pellets when a small quantity of ZnO was added, accompanied by a substantial reduction of liquid phase loss. Perfect facet lines grown up to the pellet bottom demonstrated excellent melt growth. Field distribution contour maps at the top and bottom surfaces were nearly identical. Magnetization measurements indicated that flux pinning performance continuously improved with increasing ZnO content up to 0.035 mol percent, with critical current density reaching 100 kA cm~(-2) at 3 T (77 K). Microstructure analysis by scanning tunnelling microscopy and dynamic force microscopy proved the superior microstructure of the material, consistent with the other characteristics.