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The scientific and technological interest for metal-dielectric nanocomposite thin films emanates from the excitation of localized surface plasmon resonances (LSPRs) on the metal component. The overall optical response of the nanocomposite is governed by the refractive index of the dielectric matrix and the properties of the metallic nanoparticles in terms of their bulk optical properties, size, and shape, and the inter-particle distance of separation. In order to tune the film morphology and optical properties, complex synthesis processes which include multiple steps--i.e., film deposition followed by post-deposition treatment by thermal or laser annealing--are commonly employed. In the present study, we demonstrate that the absorption resonances of Ag/AlOxNy nanocomposite films can be effectively tuned from green (~2.4 eV) to violet (~2.8 eV) using a singlestep synthesis process that is based on modulating the arrival pattern of film forming species with sub-monolayer resolution, while keeping the amount of Ag in the films constant. Our data indicate that the optical response of the films is the result of LSPRs on isolated Ag nanoparticles that are seemingly shifted by dipolar interactions between neighboring particles. The synthesis strategy presented may be of relevance for enabling integration of plasmonic nanocomposite films on thermally sensitive substrates. [ABSTRACT FROM AUTHOR]

Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer (∼1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy. [ABSTRACT FROM AUTHOR]

We compare the structure and growth modes of two series of nanocrystalline Ni/Pt multilayers deposited on glass, Si, and polyimide substrates by electron-beam evaporation at room temperature (40 °C) and at 200 °C. X-ray diffraction patterns are recorded in order of the quality of the layering to be examined. The morphology of the films is studied by atomic force microscopy. The roughness of the samples is found to depend on the substrate and the total thickness, following a power law. The crystal structure, the shape of the crystallites, and the layering of the samples were determined by transmission electron microscopy. Differences in the shape of the crystallites and the surface morphology between the two series of samples are observed and they are understood within the framework of structural zone models. Finally, it is demonstrated the large stability of the multilayer structure for a period of at least 12 years. [ABSTRACT FROM AUTHOR]

We report on magnetic and magneto-optic property aspects of nanocrystalline Ni/Pt multilayers grown by e-beam evaporation at room temperature. X-ray diffraction and atomic force microscopy measurements show high degree of multilayer sequencing and formation of nanocrystals with a relatively narrow size distribution. Magneto-optic polar Kerr effect experiments reveal a spin-polarized Pt contribution at around 3.3 eV and enhanced room temperature Kerr rotation for samples with very thin Pt layers surrounded by thicker Ni layers. The uniaxial anisotropy constants are obtained by simulating the magnetization curves and a tendency for perpendicular magnetic anisotropy is observed. [ABSTRACT FROM AUTHOR]

Bulk amorphous PdCuNiP alloys have been prepared from the liquid state by means of solidification under an argon atmosphere. The addition of a small amount of Fe (∼5 at. %) results in the formation of nanocrystalline inclusions inside the residual amorphous matrix. Element-specific near-edge x-ray absorption fine-structure spectroscopy provides information on the electronic structure and symmetry properties of the samples. In combination with conventional θ–2θ x-ray diffraction mesurements, it allows for the investigation of the modifications in structure after the addition of Fe, as well as for the determination of the most probable crystalline phases. The results are discussed in terms of thermodynamics. [ABSTRACT FROM AUTHOR]

The n-type and p-type cuprous oxide thin films were electrodeposited potentiostatically in acetate and lactate baths, respectively. Sulfur treatment of n-type and p-type cuprous oxide surfaces were achieved using gaseous (NH4)2S. Sulfur-treated Cu2O films were annealed in air at 100, 150, 200, 250, 350, and 450 °C for unique times to obtain the best photocurrent. Unannealed and annealed samples of sulfur-treated and untreated cuprous oxide were then investigated using high-energy X-ray diffraction (HEXRD). The HEXRD measurements and the pair distribution function (PDF) analysis revealed that the sulfur treatment leads to the formation of crystalline CuS on Cu2O film surfaces. The present study also shows that the sulfur treatment causes minor structural changes in Cu2O samples due to the formation of CuS. It was observed that the sulfur-treated cuprous oxide samples retarded the formation of CuO at higher temperatures showing good thermal stability and enhancement of the photoactivity of the n-type and p-type cuprous oxides. [ABSTRACT FROM AUTHOR]