ELECTRONIC-STRUCTURE AND INTERLAYER EXCHANGE COUPLING IN FE/CR SUPERLATTICES

We use self-consistent total-energy supercell band calculations to study the electronic structure of b.c.c. Fe/Cr magnetic multilayers. We find that, for n layers of Cr sandwiches between three layers of Fe, alternate Fe layers prefer ferromagnetic order for n = 3 and antiferromagnetic order for n = 4, 5, 6, and 7. The magnetic coupling is shown to result from an interplay between direct <<d-d>> hybridization of Fe and Cr atoms, and indirect exchange coupling through the <<sp>> electrons.