Epitaxy and lattice distortion of V in MgO/V/MgO(0Â 0Â 1) heterostructures

The growth temperature depencence of the epitaxy and lattice distortion of 40 Å thick V(0 0 1) films deposited on MgO(0 0 1) by triode sputtering is presented. High-quality epitaxial films are obtained for deposition temperatures between room temperature (RT) and 400 °C. For these temperatures, V grows under compression in the surface plane, matching almost perfectly the in-plane MgO lattice by a 45° rotation, irrespective of the deposition temperature and yielding to the formation of coherent V-MgO interfaces. Correspondingly, the out-of-plane V lattice parameters exhibit an expansion, maximum for room temperature deposition, that gradually decreases as deposition temperature increases. A strong reduction and the extinction of the V(2 0 0) diffraction peak is observed for 500 and 600 °C deposition temperatures, respectively, probably due to the V amorphization for these deposition temperatures.