7 research outputs found
Original surface morphology of epitaxial NiO layers grown on MgO(110)
International audienc
Formation of tetrahedral islands in epitaxial NiO layers deposited on MgO(111)
International audienc
Growth and relaxation mechanisms in La0.66Sr0.33MnO3 manganites deposited on SrTiO3(0 0 1) and MgO(0 0 1)
International audienc
Ătudes par diffraction haute rĂ©solution et rĂ©flectivitĂ© de films minces Ă©pitaxiĂ©s
The studies we present concern the general researches involved in order to understand the growth mechanisms of thin films deposited on oriented substrates. Among the different investigation technics of the thin layers, X-ray diffraction and reflectivity will be discussed through two applications. In a first step, thediffraction presented, illustrated by reciprocal space mapping, will give information about the layer state of stress and the lattice distorsion of LaSrMnO deposited on SrTiO. The results obtained are discussed and compared to those given by electron microscopy. In a second step, we will present an application of reflectivity concerning a very roughness surface of platinum deposited on MgO showing an island growth process. We will verify that reflectivity can lead to the determination of the recovered rate of the surface, even if some problems exist in the simulation of the whole data set. Results obtained in electron microscopy will complete those issued from reflectivity.Les Ă©tudes que nous allons prĂ©senter sont Ă replacer dans le contexte gĂ©nĂ©ral de la comprĂ©hension des mĂ©canismes de croissance des films minces dĂ©posĂ©s sur des substrats orientĂ©s. Parmi les diverses techniques d'investigations des couches minces, la diffraction et la rĂ©flectivitĂ© des rayons X vont ĂȘtre abordĂ©es Ă travers deux applications. Nous verrons tout d'abord que la diffraction, illustrĂ©e par la cartographie en deux dimension du rĂ©seau rĂ©ciproque, permet de remonter Ă l'Ă©tat de contrainte ainsi qu'Ă la dĂ©formation de la maille de LaSrMnO dĂ©posĂ© sur SrTiO. Les rĂ©sultats dĂ©duits de ces mesures seront discutĂ©s et comparĂ©s Ă ceux obtenus en microscopie Ă©lectronique. Dans la suite de l'article, nous verrons une des applications de la rĂ©flectivitĂ©, sur une surface trĂšs perturbĂ©e de platine dĂ©posĂ© sur MgO et prĂ©sentant une croissance en Ăźlots. Nous verrons que la rĂ©flectivitĂ© permet d'estimer le taux de recouvrement de la surface, mais que des problĂšmes persistent dans la simulation de l'intĂ©gralitĂ© des donnĂ©es expĂ©rimentales. Les rĂ©sultats obtenus en MET viendront complĂ©ter ceux issus de la rĂ©flectivitĂ©