Structure of epitaxial Gd2O3 films and their registry on GaAs(100) substrates

The structure and alignment of epitaxial molecular-beam-epitaxy-grown single-crystal Gd2O3 films on GaAs(100) are studied using secondary electron imaging. We have found that the 115 Angstrom thick Gd2O3 film has a cubic structure. The {[}110] axis is aligned perfectly with the surface normal of the substrate. The secondary electron patterns are recorded during sequential sputtering with 1000 eV Ne+ ions, They show that the {[}001] and {[}(1) over bar 10] directions of the film overlap with the {[}011] and {[}01 (1) over bar] directions of the substrate with a high degree of site registry of atoms at the interface. Copyright (C) 2000 John Wiley & Sons, Ltd.