Bean-Livingston barriers A new source for magnetic irreversibility in YBa₂Cu₃O₇ crystals

We present new measurements of the field distribution in untwinned single crystal of YBa2Cu3O7, using an ultra-sensitive local Hall-probe technique. In the temperature range 75 K to Tc (92.5 K), there is no field gradient along the sample when the external field is reduced. This indicates that Bean-Livingston surface barriers are the main source of magnetic irreversibility in this temperature range. © 1992.