Effects of dimensional crossover on flux pinning in a model high-Tc superconductor: YBa2Cu3O7-δ/(PrxY1-x)Ba2Cu3O7-δ superlattices

Superlattices of one-unit-cell-thick YBa2Cu3O7-δ, layers with (PrxY1-x)Ba2Cu3O7-δ were fabricated as a model system to study the effects of magnetic coupling on flux pinning in high-Tc superconductors. The sample can be transformed from an S/S to an S/N structure by increasing the temperature from below to above the Tc of the intercalating (PrxY1-x)Ba2Cu3O7-δ layer. Dramatic changes in the characteristics of the magnetic field and angle dependence of the critical current density, Jc(B,Θ), caused by a 3D to 2D crossover were observed. The result demonstrates the significance of the dimensionality to the flux pinning in these materials with layered structures.