Critical currents and flux creep in melt powder melt grown YBa2Cu3O7superconductors

Abstract
Melt Powder Melt Grown samples with different amounts of artificially introduced 211-precipitates were prepared and investigated by optical microscopy, DC-magnetization and AC-susceptibility measurements. The results are discussed in terms of critical current densities, flux-creep and irreversibility lines. Large shifts of the irreversibility lines as compared to single crystals and ceramics as well as high critical current densities have been observed.