Critical current of tridimensional La1.85Sr0.15CuO4-delta disordered Josephson junction arrays - dependence with the magnetic field

This paper deals with the magnetic field (H) dependence of the critical cur rent of a tridimensional disordered Josephson junction array. The average c ritical current of an array of La1.85Sr0.15CuO4-delta is determined through the AC-susceptibility measured with an excitation field of amplitude h. Th e critical field H-c, necessary to switch off super-currents through the we ak-links at the working temperature is also obtained. This configuration re lies on chi (n)(h)- instead of chi (j)(H) - to determine the critical curre nts, what proved to be particularly useful for experimental setups with exc itation and applied fields parallel to each other, a case in which the stat ic flux imposed to the array affects chi (j) much more severely than chi (n ). (C) 2001 Elsevier Science B.V. All rights reserved.