STUDY ON THE DIMENSIONALITY OF FLUX DYNAMICS IN SUPERCONDUCTING YBCO PYBCO SUPERLATTICES/

Angular dependent critical current densities for superconducting YBa2C u3O7-y/ Pr0.5Y0.5Ba2Cu3O7-y superlattices and a pure YBa2Cu3O7-y thin film were measured to investigate the influence of temperature, thickn ess of each YBa2Cu3O7-y layer and the applied magnetic filed on the di mensionality of flux dynamics (DFD). It was found that the DFD in the superlattice (48 Angstrom/24 Angstrom) x 20 exhibits a 2D behavior at t = 0.65, but that it deviates from the 2D behavior as t = 0.92. By in creasing the thickness of each YBa2Cu3O7-y layer from 48 Angstrom to 1 20 Angstrom, the DFD becomes closer to 2D at t = 0.92 under H = 0.1 T. The DFD in the superlattice (120 Angstrom/24 Angstrom) x 8 exhibits a 2D behavior at t = 0.92 if the ab-plane component of applied magnetic field H-ab is smaller than 1 T, but it deviates from 2D if H-ab is la rger than 1 T. The flux mechanics are discussed.