The structural and magnetic characterisation of MBE-grown FeMn/NiFe exchange-biased bilayers

Abstract

Summary form only given. The exchange biasing which results from magnetic exchange interactions at the interface between a ferromagnetic (FM) and an antiferromagnetic (AFM) material has attracted much attention because of its enormous application possibilities, most of which have been restricted to polycrystalline materials. In the present study, we report the epitaxial growth of exchange biased FM/AFM films and compare the magnetic properties with those of sputtered samples. Thin films of Si[111]/Cu 2nm/NiFe 6nm/FeMn (8, 10, 12)nm/Cu 2nm were grown in a magnetic field of about 200 Oe using molecular beam epitaxy (MBE). Chemical and thermal etching of the substrate, as well as insertion of a Cu buffer layer, were used to obtain epitaxial growth of the magnetic layers. The structural characterisation was performed by reflection high-energy electron diffraction (RHEED) and high resolution electron microscopy (HREM), and the magnetic properties were measured by vibrating sample magnetometry (VSM).