Instabilites in ultrathin Fe-rich alloy films on (100)

Abstract We have studied the correlation of LEED reconstructions and magnetic properties of Fe-rich Fe x Ni 1− x and Fe x Mn 1−x / Cu (1 0 0) 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.