On the anomalous pinning properties gf the C15 lavas phase superconductor CeRu2

We report the anomalous field (H) dependence of pinning force density F-p a s deduced from our magnetization measurements on the single-crystal and pol ycrystalline samples of CeRu2. It is shown that, contrary to a single maxim um in other hard type II superconductors, CeRu2 samples exhibit two distinc t peak features in their F-p-H plots. Our results show that the scaling of F-p With the applied magnetic field at different temperatures cannot be des cribed by the conventional Kramer model based on crossover from a line-brea king regime to a flux-line lattice shearing regime.