1,721,624 research outputs found
Interfacial reactivity and morphology at the Au/NiO(001) interface
No full textThe interest on metal-oxide interfaces is stimulated stimulated by the applications in many fields, such as catalysis, magnetic ecording, hard coatings. In the first stages of growth, gold nanoparticles dispersed on different oxides exhibit unusual electronic properties, depending on cluster size and gold-substrate interaction [1,2]. In particular a partial charge transfer
can occur, especially when the substrate is defective since gold tends to nucleate on oxygen vacancies. Thus the properties of goldoxide systems are critically dependent on interface reactions, in turn influenced by substrate preparation. A deeper understanding of the reactivity at the gold-oxide interface is essential to determine and control properties and behaviour of supported gold clusters. In this work we present a study of Au nucleation on top of 10 ML NiO film on Ag(001). By means of XPS, XPD and STM/AFM we studied electronic properties and morphology of the first stages of growth. It was previously reported that deposition of 15 A Au on NiO/Ag(001) causes oxide reduction [3]. We provide detailed and quantitative description
of the chemical interactions at this interface. From these results we aim to determine a relation between NiO reduction and morphological modifications (cluster formation and step decoration) in order to understand the driving force of the reduction process. Similar metal-oxide interfaces have been
also studied [4,5] to identify a general trend
in nucleation and reaction processes. In particular Fe, Pt on NiO and Fe, Pt, Au on MgO have been comparatively investigated.
[1] A. Sanchez, S. Abbet, U. Heiz, W.-D. Schneider, H. Hkkinen, R.N. Barnett, U. Landman, J. Phys. Chem. A 103(1999) 9573
[2] Z. Yang, R. Wu, D.W. Goodman, Phys. Rev. B 61 (2000) 14066
[3] R. de Masi, D. Reinicke, F. Mller, P. Steiner, S. Hfner, Surf. Sci. 515 (2002) 523
[4] S. Benedetti, P. Luches, M. Liberati, S. Valeri, Surf. Sci. 572 (2004) L348
[5] P. Luches, S. Benedetti, M. Liberati, F. Boscherini, I.I. Pronin, S. Valeri, Surf. Sci., in pres
Onjnoheja e Amantias, kullesa dhe qepshe prej bronzi / L’oinochoé d’Amantia, passoirs et luches en bronze
No full textBereti Vasil. Onjnoheja e Amantias, kullesa dhe qepshe prej bronzi / L’oinochoé d’Amantia, passoirs et luches en bronze. In: Iliria, vol. 35, 2011. pp. 175-206
Applications of the matrix-assisted pulsed laser evaporation method for the deposition of organic, biological and nanoparticle thin films: A review
No full text
Reducible oxides as ultrathin epitaxial films
No full textThis chapter reviews and discusses recent work on two-dimensional films of reducible oxides supported on metal substrates. In general, peculiar chemical and structural phases, different from the bulk ones, can be stabilized depending on the oxygen chemical potential, on kinetic processes and on the specific substrate used. A peculiarity of reducible oxides is that the observed phases can often be reversibly transformed one into the other by applying reducing and oxidizing treatments
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
Structure, morphology and reducibility of epitaxial cerium oxide ultrathin films and nanostructures
No full textCerium oxide is a very interesting material that finds applications in many different fields, such as catalysis, energy conversion, and biomedicine. An interesting approach to unravel the complexity of real systems and obtain an improved understanding of cerium oxide-based materials is represented by the study of model systems in the form of epitaxial ultrathin films or nanostructures supported on single crystalline substrates.
These materials often show interesting novel properties, induced by spatial confinement and by the interaction with the supporting substrate, and their understanding requires the use of advanced experimental techniques combined with computational modeling. Recent experimental and theoretical studies performed within this field are examined and discussed here, with emphasis on the new perspectives introduced in view of the optimization of cerium oxide-based materials for application in different fields
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