A periodic array of nanoscale twin boundaries was formed within melt-processed YBa2Cu3O7-δ with Ru additions. The pinning efficiency of the resultant material was strongly modified in the presence of this disorder. The arrangement of regular twin boundaries along the c-axis had a strong influence upon the irreversibility line and critical current density. A characteristic kink was found at Bcr = 2.75T on the c-axis irreversibility line; indicating correlated disorder. The field tilt angle below which pinning by the twin boundary was effective was found to be about 40°. Detailed investigations of glassy dynamics showed that the twin boundary structure which appeared would inhibit the motion of vortices in the variable-range-hopping regime below the effective matching field.

Bose-Glass Signatures in Bulk YBa2Cu3O7-δ with Periodic Array of Nanoscale Twin Boundaries. L.Shlyk, K.Nenkov, G.Krabbes, G.Fuchs, C.Mickel, B.Rellinghaus: Superconducting Science and Technology, 2006, 19[7], S472-7