Fabrication and characterization of thin-wall YBCO single-domain samples

Thin-wall geometry implies a regular network of holes in a bulk, centimetric sample so that its effective thickness can be considered to be smaller than 1.5 mm. Thin-wall geometry offers a significant potential for helping the oxygenation process, mechanical reinforcement and thermal stabilization. Thin-wall geometry was obtained by drilling holes in slightly sintered pellets or by pressing pellets with embedded needles. The growth of a single domain, up to 50 mm in diameter, on such thin-wall geometry pellets was confirmed, despite the presence of many-hole patterns, by in situ high-temperature video monitoring. A significant decrease of porosity and cracks is observed, associated with the reduction of diffusion paths produced by thin-wall geometry. The improvement of the material quality is established by a significant increase ( about 40%) of the magnetic trapped field in thin-wall samples.