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The morphology, epitaxy, band alignment, and optical response of silver nanoparticles on ZnO(10 (1) over bar0) have been analyzed by microscopy, electron diffraction, photoemission and differential reflectivity. At 700 K, clusters tend to nucleate and grow exclusively along [010]-oriented polar steps and corners and not on flat terraces or nonpolar [001] steps. This preference leads to a specific epitaxy Ag[1 (1) over bar0](111) II ZnO[010] (10 (1) over bar0) with a large lattice mismatch along the dense row of the metal. The experiments have been rationalized through ab initio simulations. A much lower adsorption energy is obtained for the O-terminated steps with a charge transfer from silver to oxygen that corroborates the variation of ionization energy observed in photoemission and the presence of cationic silver. This anisotropy of growth reverberates in the plasmonic response of the metallic particles. The growth and epitaxy of metals on polar (0001) and nonpolar (10 (1) over bar0) orientations of ZnO are discussed in terms of surface/step polarity compensation in the light of the present findings.

A coated metallic substrate and fabrication method The present invention relates to a coated metallic substrate comprising, at least; one layer of oxides, such layer being directly topped by an intermediate coating layer comprising Fe, Ni, Cr and Ti wherein the amount of Ti is above or equal to 5 wt.% and wherein the following equation is satisfied: 8 wt.% < Cr +Ti < 40 wt.%, the balance being Fe and Ni, such intermediate coating layer being directly topped by a coating layer being an anticorrosion metallic coating., La présente invention concerne un substrat métallique revêtu et un procédé de fabrication. La présente invention concerne un substrat métallique revêtu comprenant, au moins ; une couche d’oxydes, ladite couche étant directement surmontée d’une couche de revêtement intermédiaire comprenant Fe, Ni, Cr et Ti, la quantité de Ti étant supérieure ou égale à 5 % en poids et dans laquelle l’équation suivante est satisfaite : 8 % en poids < Cr +Ti < 40 % en poids, le reste étant Fe et Ni, une telle couche de revêtement intermédiaire étant directement surmontée d’une couche de revêtement qui est un revêtement métallique anticorrosion.

The present work reports a general method for the calculation of t he polarizability of a truncated sphere on a substrate. A multipole ex pansion is used, where the multipoles are not necessarily localized in the center of the sphere but can freely move on the revolution axis. From the weak formulation of the boundary conditions, an infinite set of linear equations for the multipole coefficients is derived. To obta in this set, the interaction between the island and the substrate is t aken into account by the technique of image multipoles. For numerical implementation, this set is truncated at an arbitrary mu ltipole order. The accuracy of the method is jugded through the stabil ity of the truncated sphere polarizability and the the fulfilment of t he boundary conditions which are demonstrated to be satisfied in large regions of the parameter space. This method brings an improvement wit h respect to the Bedeaux's case \cite{Wind87a,Wind87b} where the multi poles are located in the center of the sphere., Comment: Revtex, 24 pages including 11 figures. Submitted to Phys. Rev. B