Transport critical current dependence on magnetic fields in ceramic high temperature superconducting samples

Abstract: The expression for the Josephson current flowing through the rectangular junctions was averaged over the values determining its properties in the case when magnetic field is less then first critical magnetic field of superconducting grains. The averaging results permit to explain the earlier performed experimental investigations of the scaling properties of critical state in random 3-d Josephson net created by transport current. At low magnetic field the average Josephson current is a quadratic function of the magnetic field and at high field the average current is an inverse quadratic function. [Copyright &y& Elsevier]