MAXIMUM IN THE TEMPERATURE-DEPENDENCE OF THE CRITICAL-CURRENT IN BULKRANDOM JOSEPHSON NETWORKS

The superconducting properties of the metastable alloy Zn-Sb are studi ed in a set of intermediate states of a bulk sample during its transfo rmation to the insulating state. As the temperature is lowered below t he transition, the critical current rises till 0.7T(c), then drops and finally reaches the limiting value. The latter scales with the normal resistance of the sample as R(n)(-2), whereas at the maximum at 0.7T( c) the scaling power is different, R(n)(-3/2). A comparison with the p roperties of small superconducting tunnel junctions is made. (C) 1995 American Institute of Physics.