Penetration of a weak magnetic field into a Josephson junction region with magnetic impurities at the barrier near Tc

The problem of the penetration of a weak external magnetic field into an SIS junction with ordered magnetic impurities in the tunnel barrier region is analyzed in the context of the Ginzburg-Landau theory. A formula is obtained which describes magnetic field distribution within the junction. It is shown that the London penetration depth is maximum when the exchange field of the impurity spins reaches a critical value that corresponds to the breakage of the weak link between the superconducting regions of the junction.