LOCAL DENDRITE DEVELOPMENT DURING SEEDED PERITECTIC SOLIDIFICATION OFLARGE YBA2CU3O7-DELTA GRAINS

The growth morphology of large YBa2Cu3O7-delta grains during peritecti c solidification has been reported to be responsible for the generatio n of processing defects, such as platelets, and an inhomogeneous distr ibution of 211 particles, both of which influence significantly the su perconducting properties of the fully processed material, The present study demonstrates both experimentally and theoretically the formation of local dendrites at macroscopically planar YBa2Cu3O7-delta growth f ronts which propagate along different crystallographic directions and identifies these as key growth features of the peritectic solidificati on process.