From anisotropic dots to smooth RFe2(110) single crystal layers (R = rare earth)

Single crystal RFe2(110) films were grown by molecular beam epitaxy to a total thickness of 1000 Angstrom at different substrate temperatures ranging from 450 degreesC to 660 degreesC. The first stages of growth and the surface morphology of the deposited layers have been studied using Reflection High Energy Electron Diffraction (RHEED) and Atomic Force Microscopy (AFM). The growth is first strained but further deposit induces the formation of three-dimensional fully relaxed islands. Subsequently, the morphology of the RFe2(110) nanosystems evolves from anisotropic dots to a smooth surface, as a function of the preparation parameters, i.e, nominal thickness and substrate temperature. It also depends on the rare earth involved in the compound.