Comparison of the critical current anisotropy in YBaCuO and BiSrCaCuO films

This paper reports on laser deposition using a Siemens XP2020 Excimer Laser, thin single-crystalline YBa2Cu3O7-x and Bi2Sr2CaCu2Ox films prepared on <100> SrTiO3 and LaAlO3 substrates. The CuO planes of the films are always parallel and the c-axes perpendicular to the film plane. The critical current density jc was measured in the whole superconducting temperature range in magnetic fields up to 7 T as a function of the angle θ between the field direction and the c-axis. At 4.2 K, jc (B perpendicular c) is almost field-independent (up to 7 T) and, at 7 T, is about one order of magnitude larger than jc (B parallel c) for both types of superconductors