Behavior critical for bond diluted n-vector model in the effective field theory

In the present work the bond-diluted n-vector model on the simple cubic lattice is studied by applying the effective field theory for a cluster with two spins. The critical temperature and percolation concentrations for XY and Heisenberg models, as well the phase diagram in the T–p plane, respectively, are obtained and the results, when compared with the standard mean field approximation, are an improvement, even for small size clusters.