The transport current dissipation in the high Tc superconducting ceramic La1.85Sr0.15CuO4-δ shows a sin2 Θ voltage dependence where Θ is the angle between the transport current and the magnetic field. This result and the experimental evidence of an angle independent critical current cannot be explained by the conventional description of flux motion in homogeneous type II superconductors. The results are analyzed in the framework of a granular system where pinning is induced by the topological distribution of current flowing through a multiply connected medium. The dissipation in the superconducting state is found to be due to two additive contributions, one induced by the movement of magnetic flux and the other associated to dissipation in the Josephson junction.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry