Field-induced metastable states in ultrathin films of fcc Fe/Cu(100)

The thickness dependence of both the perpendicular and in-plane magnetization is observed for pseudomorphic ultrathin, fcc Fe epitaxial films grown on room temperature Cu(100). Ferromagnetically ordered 3.5-monolayer-thick films display both in-plane and perpendicular remanence. Perpendicular remanence, lost after a 9.0 kOe static field is applied perpendicular to the film plane, can be restored by either heating or applying large in-plane fields. These field-induced metastable states are interpreted in terms of magnetoelastic effects which modify the exchange and anisotropy constants both perpendicular to and within the film plane.