Unoccupied electronic states of epitaxial iron layers on Cu(100)

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

The scientific enthusiasm for ultrathin Fe films on Cu(001) has now lasted for more than 20 years. Is there ferromagnetic iron with a face-centred cubic (fcc) structure? Does ferromagnetism in Fe hinge on the body-centred cubic (bcc) structure? In this contribution, we try to establish that the electron system gives evidence of ferromagnetic behaviour with fcc-like electronic bands. We examine a crystal-induced surface state, which is characteristic of fcc surface order. Furthermore, we compare electronic signatures of fcc and bcc: the d-band exchange splitting, image-potential-state energies and the work function. We conclude that, from the viewpoint of the electronic structure, Fe on Cu(001) is found to be ferromagnetic throughout the fcc-like phase. This result raises a new question: how much deviation from the relaxed fcc order is acceptable without losing the electronic signature of fcc?

Effect of magnetic doping on the electronic states of Ni

Angle-resolved photoemission is used to determine the change in the electronic states of Ni induced by doping with Fe and Cr. Well-defined spin and k states are selected using high energy and k resolution combined with single crystal alloys. Iron suppresses the mean free path of minority spins only, while chromium suppresses both spins and decreases the magnetic splitting. The strong variation of these effects from one impurity to the other supports the concept of magnetic doping.