LA1.85SR0.15CUO4-DELTA BICRYSTAL GRAIN-BOUNDARY JOSEPHSON-JUNCTIONS

We have investigated La1.85Sr0.15CuO4-delta grain boundary Josephson j unctions (GBJs) fabricated on [001] tilt SrTiO3 bicrystals with misori entation angles of 24 degrees and 36.8 degrees. The resistive transiti on and the current-voltage characteristics of the GBJs are found to be close to those predicted by the resistively shunted junction (RSJ) mo del. Their product of the critical current density, J(c), and the norm al resistance times area rho(n), scales proportional to about (J(c))(q ) with q = 0.5-0.6 similar to what is found for YBa2Cu3O7-delta GBJs. By analyzing Fiske resonances the Swihart velocity of the GBJs and the ab-plane London penetration depth of La1.85Sr0.15CuO4-delta are obtai ned to (c) over bar = 2.5 x 10(6) m/s and lambda(L) = 200 nm at 4.2 K, respectively. (C) 1996 American Institute of Physics.