Mechanism of characteristic shape of resistive transition in Bi2Sr2CaCu2O8 films made by laser evaporation

We measured the temperature dependence of resistivity, (T, H), of Bi₂Sr₂CaCu₂O₈ thin films in magnetic fields. These films have a preferential orientation of the c-axis perpendicular to a surface of the substrate. We could not observe any meaningful anisotropy of the characteristic shape of the resistive transition between two cases of the current flow parallel and perpendicular to the magnetic field in the basal plane. Therefore, it is very difficult to ascribe the broadness to any origin due to the Lorentz force produced by an external current.