Dependence of critical current on field angle in off-c-axis grown Bi2Sr2CaCu2O8 film

Abstract

Critical current measurements for varying angles of applied field have been performed on Bi2Sr2CaCu2O8 thin films grown on 10° vicinal (001) substrates. Measurements were performed on current tracks orientated both parallel (L) and transverse (T) to the vicinal steps. No Josephson vortex channeling effect was observed, in contrast to results previously obtained on both oxygenated and deoxygenated YBa2Cu3O7−δ films grown on vicinal substrates. In addition, no force-free peak was observed when the applied field was parallel to the current. This provides experimental evidence that there is a difference between the pancake coupling mechanism in YBa2Cu3O7−δ at small field angles where Josephson vortices are present and that in Bi2Sr2CaCu2O8.