A nearly lattice-matched Gd2O3/Si(111) hetero-epitaxy was demonstrated using molecular beam epitaxy (MBE). Detailed structural studies find that the nano thick Gd2O3 films have a cubic phase with a very uniform thickness, an excellent crystallinity and atomically sharp interfaces. These features are characterized by the bright, streaky reconstructed reflection high-energy electron diffraction (RHEED) patterns at the initial oxide growth, the pronounced interference fringes in the X-ray reflectivity curve as well as in the crystal truncation rod around the substrate diffraction peaks using the high-resolution X-ray diffraction. The (111) axis of the thin oxide is oriented parallel to the substrate (111) normal with a 60 degrees in-plane symmetry rotation. (c) 2006 Published by Elsevier B.V.