The role of interfacial structure in determining magnetic behaviour in MBE-grown Fe 3O 4–MgO multilayers on MgO(001)

Abstract

The atomic structure at the Fe 3O 4–MgO interface and its role in defining magnetic behaviour in Fe 3O 4–MgO multilayers, grown by MBE on MgO(001), has recently been a subject of much interest and controversy: the existence of a “dead” magnetic layer at the interface has been proposed to explain why ultra-thin magnetite layers become nonmagnetic. By using Mössbauer probe layers it was shown that this model is incorrect. In this paper we present additional structural evidence, from X-ray reflectivity and RHEED measurements, showing that the magnetite layers have the same structure and composition at the interface and in the bulk in agreement with a uniform magnetic structure throughout the entire layer.