1,720,992 research outputs found
Investigation by electrochemical and deflectometric techniques of silicon dissolution and passivation in alkali
No full textMonitoring anodic silicon dissolution in acidic fluoride electrolyte by the mirage effect
No full textSurface Characterization of Culns(2) With Lamellar Morphology
No full textLamellar crystals of CuInS2 grown in a steep temperature gradient have been characterized. Dispersive x-ray analyses show a predominant stoichiometry Cu/In/S = 1/1/2 and inclusions of Cu deficient phases. The cleaved surface is smooth, but after chemical etching a fine structure appears, with a great number of closely packed microcrystals of a dendritic shape. X-ray diffraction spectra of lamellae only show the reflections of the CuInS2 (112) and of the CuIn5S8 (111) lattice planes, indicating a strongly oriented structure. Depth profiles of CuInS2 lamellae investigated with x-ray photoelectron spectroscopy show the presence at the cleaved surface of Cu deficient phases like CuIn5S8, which are a few tens of nanometers thick. The lamellar growth mechanism is discussed on the basis of these findings. X-ray photoelectron spectroscopy and secondary ion mass spectrometry investigations show that the oxidation behavior of the lamellar material resembles that of traditional CuInX(2) phases (X = S, Se)
FIB lithography of nanoporous gold slits for extraordinary transmission
No full texthere is a growing interest in discovering new materials for sensing purposes that provide better sensitivity and efficiency. Thanks to a greatly enhanced surface-to-volume ratio, nanoporous gold reveals benefits for better reaction efficiency and detection sensitivity purposes. Moreover plasmonic properties in the near-IR range assure employment in plasmonic devices. Here we present our work of design, fabrication and characterization of nanoporous gold slit arrays that support the phenomenon of extraordinary transmission of the incident light. The gold surface of fabricated samples has been coated with dodecanethiol and the optical response to functionalization has been analyzed in zero-order transmission
Nb electrodissolution in aqueous alkali: dependence on the alkali metal
No full textNb electrodissolution is studied in solutions of alkali metal hydroxides MOH (M/Li, Na, K, Rb and Cs). The j /E curves show
in all cases a dissolution/passivation peak followed by a current plateau. The current shows a marked dependence on the cation M:
the peak current density jpk goes through a maximum forM/K and the plateau current density jpl increases monotonically with the
atomic number of M. Electrochemical impedance spectroscopy indicates that in the plateau region, a similar barrier oxide is present
over the metal substrate in all solutions. XPS analyses show that polarisation causes, in certain cases, formation of a porous film of
alkali metal niobates or mixed oxides, probably by a mechanism of dissolution/precipitation. It is proposed that the peak current is controlled by both the solution basicity and the solubility of this layer, whereas the dependence of the plateau current on M reflects
the variations in solution basicity and in the specific ability of the metal cations to promote dissolution of the barrier oxide
Preparation of anodes for oxygen evolution by electrodeposition of composite oxides of Pb and Ru on Ti
No full textNanoporous gold plasmonic structures for sensing applications
Full text linkThe fabrication, characterization and functionalization of periodically patterned nanoporous gold layers is presented. The material shows plasmonic properties in the near infrared range, with excitation and propagation of surface plasmon polaritons. Functionalization shows a marked enhancement in the optical response in comparison with evaporated gold gratings, due to a great increase of the active surface. Due to its superior response, nanoporous gold patterns appear promising for the realization of compact plasmonic platforms for sensing purposes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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