We have studied the correlation of LEED reconstructions and magnetic properties of Fe-rich FexNi1-x and FexMn 1-x/Cu(100) films. From 2 to 4 ML, the films are uniformly magnetized along the surface normal. In this thickness regime the diffraction pattern is of (n × 1) symmetry with n∼5. Above 4 ML, we observe "magnetic live surface layers" and a LEED pattern of (1 × 1) or (2 × 1) symmetry. © 2003 Elsevier B.V. All rights reserved.