Ferromagnetic Fe on Cu(001) throughout the fcc-like phase: arguing from the viewpoint ofthe electronic structure

Abstract

The scientific enthusiasm for ultrathin Fe films on Cu(001) has now lasted for more than20 years. Is there ferromagnetic iron with a face-centred cubic (fcc) structure? Doesferromagnetism in Fe hinge on the body-centred cubic (bcc) structure? In thiscontribution, we try to establish that the electron system gives evidence of ferromagneticbehaviour with fcc-like electronic bands. We examine a crystal-induced surface state,which is characteristic of fcc surface order. Furthermore, we compare electronicsignatures of fcc and bcc: the d-band exchange splitting, image-potential-stateenergies and the work function. We conclude that, from the viewpoint of theelectronic structure, Fe on Cu(001) is found to be ferromagnetic throughout thefcc-like phase. This result raises a new question: how much deviation from therelaxed fcc order is acceptable without losing the electronic signature of fcc?