Electronic structure and magnetic effects at the ideal (110) Fe/Ge interface

摘要

Ge and bcc Fe are well lattice matched, and therefore present an excellent prototype system to study magnetic effects at a metal/semiconductor interface. We study the electronic structure of the (110) Fe/Ge interface using a superlattice geometry and a parametrized tight‐binding approach. We find that seven layers of Fe and 11 layers of Ge are necessary to identify unambiguously the interface bands in this system. The Fe minority‐spin projected band structure has a large gap around theM¯ point (corner of the two‐dimensional Brillouin zone) which spans the fundamental gap in Ge. We find four distinct interface bands which lie in this mutual gap and a corresponding large density of states at the Fermi level. For the majority‐spin electrons we also find a large density of interface resonances just above the Fermi level which are strongly localized on the Ge atoms at the interface. These results are consistent with the very reactive nature of this interface seen in experimental studies.