title: HRTEM and EELS study of Y2O3/MgO thin films.
abstract: Y2O3 thin films deposited on (001)-MgO substrate have been investigated by high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy. Digital processing of the HRTEM images reveals the presence of grains with a crystallographic structure different from that of the rest of the film (Ia3). The spectrum imaging technique has been applied in vicinity of the Y2O3/MgO interface to get a better knowledge of the phases nucleated on the substrate surface. Fine structures of the O K-edge have been studied in detail; actually two kinds of spectra have been detected in the yttrium oxide thin film. These spectra have been compared to self-consistent full multiple scattering calculations (SC-FMS). One family of spectra has then been associated to the well-known Ia3 structure. The other family of spectra has been compared to calculations performed for the other known structures (such as hexagonal or monoclinic) of Y2O3 with a little success. We have finally compared these spectra to calculations performed with a particular atomic arrangement (octahedral) of Y and O atoms, which leads to a good match between experimental and calculated spectra. Our results emphasize the benefit of coupling several techniques such as HRTEM, EELS and SC-FMS for the determination of structures at the nanometric scale.
authors.affiliation: Laboratoire de Métallurgie Physique, CNRS/Université de Poitiers, UMR 6630, 86962 Futuroscope-Chasseneuil, France. frederic.pailloux@univ-poitiers.fr
authors.forename: F
authors.initials: F
authors.lastname: Pailloux
authors.forename: D
authors.initials: D
authors.lastname: Imhoff
authors.forename: M
authors.initials: M
authors.lastname: Jublot
authors.forename: F
authors.initials: F
authors.lastname: Paumier
authors.forename: R J
authors.initials: RJ
authors.lastname: Gaboriaud
authors.forename: M
authors.initials: M
authors.lastname: Jaouen