Magnetic coupling between ferromagnetic (FM) and antiferromagnetic (aFM) layers is of high importance to exchange bias and related magnetic technologies. It is essential to achieve atomically smooth and flat magnetic films onto which we can deposit transition metals (e.g. Fe, Mn and Cr) to create magnetic bi-layer systems that will allow us to probe possible magnetic coupling. In this study, we grow FM Fe and aFM Mn and Cr films on MgO(001) using molecular beam epitaxy (MBE) and investigate the surfaces using scanning tunneling microscopy (STM).

The growth experiments take place in an ultra-high vacuum (UHV)-MBE chamber, equipped with Fe, Mn and Cr effusion cells, a 20 keV reflection high energy electron diffraction (RHEED), and a quartz crystal sensor (for flux calibrations). Fe, Mn and Cr films are grown on MgO(001) over a range of sample temperatures. The prepared samples are transferred in-situ to the adjacent UHV room temperature STM analysis chamber for surface studies. The streaky RHEED patterns indicate single crystal films grown with smooth surfaces and STM topography images reveal atomically smooth and flat surfaces on each film. X-ray diffraction (XRD) confirms the (001) growth face for Fe and Cr. Magnetic force microscopy (MFM) is performed on each film to explore the magnetic domain structure. Ultimately, we aim to extend the present study to include spin-polarized STM measurements that will probe the magnetic coupling between FM and aFM layers, e.g. sub-monolayer Fe on Mn (or Cr) substrates (and vice versa).