Macrosegregation of Y 2BaCuO 5 particles in top-seeded melt textured monoliths

Abstract

Y 2BaCuO 5 (Y-211) particles distributed in the textured matrix play an important role for the superconducting properties. The Top-Seeded Melt Growth (TSMG) process always leads to a macrosegregation of Y-211. For TSMG and Multi-Seeded Melt Growth (MSMG) monoliths, the characterization of the distribution of the Y-211 particles was performed over slices in the (001) plane and (001) direction, respectively. As soon as the growth commences, a zone with a low content of less than 10 mol% of Y-211 appears. The low content of Y-211 can mainly be explained by the pushing/trapping model. This model relates the radii of the smallest trapped Y-211 particles to the growth rate. Furthermore, when the undercooling Δ T reaches 25°C, the growth front stops to push the particles and starts to trap them.