Magnetic anomaly and the peak effect in superconductingCeRu2

Abstract
We have observed an anomaly in the magnetization of CeRu2, close to Bc2 (Tc). Our careful study establishes that it is in the reversible region of the B-T phase diagram and is observed during field cooling. Hence this anomaly, which at first glance appears to be similar to the celebrated ‘‘peak effect,’’ cannot be attributed to pinning and appears to be an equilibrium property of the system.