Effects of dimensional crossover on flux pinning in a model high-Tcsuperconductor:YBa2Cu3O7−δ/(PrxY1−x)Ba2Cu3O7−δsuperlattices

Superlattices of one-unit-cell-thick YBa 2 Cu 3 O 7-δ layers with (Pr x Y 1-x )Ba 2 Cu 3 O 7-δ were fabricated as a model system to study the effects of magnetic coupling on flux pinning in high-T c superconductors. The sample can be transformed from an S/S' to an S/N structure by increasing the temperature from below to above the T c of the intercalating (Pr x Y 1-x )Ba 2 Cu 3 O 7-δ layer. Dramatic changes in the characteristics of the magnetic field and angle dependence of the critical current density caused by a 3D to 2D crossover were observed