QUANTUM-WELL STATES AND INDUCED MAGNETISM IN FE CU-N/FE BCC (001) TRILAYERS/

We have used a first-principles Green's function technique to investig ate the formation of magnetic moments in Fe/Cu-N/Fe bcc (001) trilayer s. We show that the magnetic moment in the paramagnetic spacer materia l to a first approximation may be described as a linear superposition of the magnetic profiles of two single Fe/Cu interfaces. The small dev iations from this simple superposition are shown to be a consequence o f quantum-well states confined within the paramagnetic spacer. This co nnection is confirmed by direct calculation of the state density. The results are of conceptual interest for the understanding of the exchan ge coupling.