Characteristics of flux pinning in YBa2Cu3Oy/PrBa2Cu3Oy superlattices

The resistivity of (YBa2Cu3Oy/PrBa2Cu3Oy)(n) [(YBCO/PBCO)(n)] superlattices under magnetic fields was measured to investigate the flux pinning and anisotropic superconducting properties, where n is the number of the modulation layer. The fields applied were parallel to the ab plane and the c axis of the films. The resistivity under magnetic fields shows thermally activated behavior. A power law magnetic field dependence of U(0)similar to H-alpha in YBCO/PBCO superlattices was observed. The U0XHalpha/(H-c2,H-c)(2) was observed to scale to a constant which increases linearly when the thickness of YBCO layers is increased and decreases linearly when the thickness of PBCO layers is increased. There exists both one-unit-cell YBCO and interlayer YBCO couplings in YBCO/PBCO superlattices. These couplings affect the coherence lengths. [S0163-1829(99)01010-3].