Characterization and transport properties of YBa₂Cu₃O_y/Y_xPr_1-xBa ₂Cu₃O_y, superlattices under magnetic fields using an off-axis rf magnetron sputtering technique

We report here on the growth and transport properties of YBa₂Cu₃O_y/Y_xPr_1-x,Ba ₂Cu₃O_y, superlattices. The YBa₂Cu₃O_y/Y_xPr_1-xBa ₂Cu₃O_y [(YBCO/PBCO) for x = 0 and (YBCO/YPBCO) for x = 0.5] superlattices were grown in situ in an off-axis radio-frequency magnetron sputtering system. The superlattice structure of the samples was characterized by powder X-ray diffraction. Appearance of satellite diffraction peaks near the main (001) peaks confirms the superlattice structure. Resistivity measurements carried out under magnetic fields reveal thermal activated behaviour. Hall coefficients, R_H, in mixed state show sign reversal and a diminishing of RH is observed when the thickness of the YPBCO layer is increased or the thickness of the YBCO layer is decreased. Angular dependence of the critical current density, J_c, in YBCO/PBCO superlattices shows a decoupled behaviour in the flux line dynamics as the coupling strength of the YBCO layer weakens.