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

The structure and alignment of epitaxial molecular-beam-epitaxy-grown singl e-crystal Gd2O3 films on GaAs(100) are studied using secondary electron ima ging. We have found that the 115 Angstrom thick Gd2O3 film has a cubic stru cture. The [110] axis is aligned perfectly with the surface normal of the s ubstrate. The secondary electron patterns are recorded during sequential sp uttering 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] dir ections of the substrate with a high degree of site registry of atoms at th e interface. Copyright (C) 2000 John Wiley & Sons, Ltd.