ANISOTROPIC SELF-FIELD EFFECT IN A-AXIS YBA2CU3O7-X AG/PBIN JOSEPHSON-JUNCTIONS/

We have measured magnetic diffraction patterns of critical currents of vertical geometry YBa2Cu3O7-x(YBCO)/Ag/PbIn Josephson junctions made with in-plane aligned a-axis oriented YBCO films. Anisotropic penetrat ion depths in YBCO and the resulting Josephson penetration depths give rise to diffraction patterns which are distinctly different when the magnetic field is applied in two orthogonal directions (b and c). The London penetration depths of YBCO, lambda(b), and lambda(c), are found to be similar to 2000 Angstrom and similar to 1.2 mu m, respectively, at 4.2 K. Intrinsic I(c)R(n) products of up to 0.2 mV have been obtai ned in these junctions. (C) 1996 American Institute of Physics.