Rare earth Laves phase (RFe2) superlattice structures grown at different temperatures were studied using X-ray reflectivity, X-ray diffraction, and transmission electron microscopy. The optimized molecular beam epitaxy growth condition was matched with the X-ray reflectivity simulation, showing minimum diffusion/roughness at the interfaces. Electron microscopy characterization revealed that the epitaxial growth develops from initial 3D islands to a high quality superlattice structure. Under this optimum growth condition, chemical analysis by electron energy loss spectroscopy with high spatial resolution was used to study the interface. The analysis showed that the interface roughness was between 0.6 and 0.8nm and there was no significant interlayer diffusion. The locally sharp interface found in this work explains the success of simple structural models in predicting the magnetic reversal behavior of Laves exchange spring superlattices.

Interlayer Diffusion Studies of a Laves Phase Exchange Spring Superlattice. C.Wang, A.Kohn, S.G.Wang, R.C.C.Ward: Journal of Physics - Condensed Matter, 2011, 23[11], 116001