Dimension of the collective pinning in the layered superconductor 2HNbSe2−xSx

Abstract We investigated the size effect on the flux pinning under an arbitrarily oriented magnetic field in the mixed crystals 2H NbSe 2− x S x ( x ≅ 0.3) . Our experimental results show that the flux pinning in our samples does not become two-dimensional but it is always three-dimensional within a frame of the collective pinning theory. We conclude that a different mechanism from the dimensional crossover causes the peak effect in our samples.