Spontaneous Magnetization in the Disorder Dominated Phase of the Two-dimensional Random Bond Ising Model Short Title: Magnetization in the 2d Random Bond Ising Model

The selfconsistent approach to the two-dimensional Ising model with quenched random bonds is extended to the full lattice theory described by four real fermions. A calculation of the averaged spin-spin correlation function for large separation of the spins in the disorder dominated phase indicates an exponential decay of this quantity and therefore a vanishing spontaneous magnetization. The corresponding correlation length is proportional to 1/η 2 , where η denotes the order parameter of the new phase introduced by Ziegler.