Anomalous Paramagnetic Effects in the Mixed State of LuNi2B2C

C, unlike any reported previously. It appears as a kink-like feature for H ≥ 30 kOeand becomes more prominent with increasing field. A specific heat anomaly at the correspondingtemperature suggests that the magnetization anomaly is due to a true bulk transition. A magneticflux transition from a square to an hexagonal lattice is consistent with the anomaly.