Flux penetration and Bean-Livingston barriers in Bi(2212) single crystals

We report high resolution magnetization measurements of the flux penetration of Bi(2212) single crystals in low magnetic fields. We find two well defined transition temperatures in the H-T plane where low frequency flux flow noise sets in and vanishes. We interpret the upper transition line as a magnetic irreversibility line and the lower line as a crossover line below which the Bean-Livingston barrier limits the rate of flux flow across the sample surface. (orig.)