Author
Alain Hoareau
Bio: Alain Hoareau is an academic researcher from Claude Bernard University Lyon 1. The author has contributed to research in topics: Thin film & Cluster (physics). The author has an hindex of 14, co-authored 49 publications receiving 1059 citations.
Papers
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TL;DR: The experimental structures obtained during deposition are compared to predictions of recent computer models, and very good agreement is found, suggesting that the diffusion cannot be explained by a simple atomic activated process, but rather involve collective motions of the atoms of the cluster.
Abstract: We present a quantitative study of the diffusion of spherical antimony clusters deposited on graphite surfaces. The experimental structures obtained during deposition are compared to predictions of recent computer models, and very good agreement is found. From this comparison we can obtain the diffusion coefficient of large antimony clusters containing around 2300 atoms moving on a graphite substrate: we find ${D\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}D}_{0}\mathrm{exp}({\ensuremath{-}E}_{a}/{k}_{B}T)$ with ${D}_{0}\ensuremath{\approx}1.6\ifmmode\times\else\texttimes\fi{}{10}^{4}{\mathrm{cm}}^{2}/\mathrm{s}$ and ${E}_{a}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.7\ifmmode\pm\else\textpm\fi{}0.1\mathrm{eV}$. This large value of ${D}_{0}$ suggests that the diffusion cannot be explained by a simple atomic activated process, but may rather involve collective motions of the atoms of the cluster.
210 citations
TL;DR: In this paper, the specific properties of free clusters and the formation of new cluster-assembled materials using the low energy cluster beam deposition (LECBD) technique are discussed with special attention to new observed structures.
Abstract: In this paper the specific properties of free clusters and the formation of new cluster-assembled materials using the low energy cluster beam deposition (LECBD) technique are discussed. Recent results obtained for free clusters are summarized with special attention to new observed structures. As for the specific structures and properties of cluster-assembled materials, two main aspects are specially emphasized: the memory effect of the free cluster properties leading to the formation of new phases and the effect of the specific nanostructure of the cluster-assembled materials related to the random cluster stacking mechanism characteristic of the LECBD. These effects and the corresponding potential applications are illustrated using some selected examples: new diamond-like carbon films produced by fullerene depositions (memory effect) and grain effect on the magnetic properties of cluster-assembled transition metal films.
179 citations
TL;DR: In this paper, the first stages of growth of thin films produced by low-energy cluster beam deposition (LECBD) on graphite are analyzed in the framework of new models including three physical ingredients, which are the deposition, the diffusion and the aggregation of the clusters.
121 citations
71 citations
TL;DR: Ces resultats peuvent etre interpretes pour des structures icosaedriques a empilement compact, similaires a celles observees dans des agregats de gaz nobles.
Abstract: Barium clusters are produced by the inert-gas condensation technique. The observed size distribution shows large peaks at n=13, 19, 23, 26, 29, 32, as well for singly charged clusters as for doubly and triply charged clusters. These results can be interpreted by icosahedral close-packing structures, similar to those observed in noble-gas clusters.
45 citations
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TL;DR: Carbon nanotubes have been shown to be useful for miniaturized electronic, mechanical, electromechanical, chemical and scanning probe devices and materials for macroscopic composites.
1,256 citations
TL;DR: In this article, a detailed description of the conduction mechanism and the main parameters that control the conductivity of ITO films are presented, on account of the large varieties and differences in the fabrication techniques.
Abstract: Tin doped indium oxide (ITO) films are highly transparent in the visible region, exhibiting high reflectance in the infrared region, and having nearly metallic conductivity. Owing to this unusual combination of electrical and optical properties, this material is widely applied in optoelectronic devices. The association of these properties in a single material explains the vast domain of its applicability and the diverse production methods which have emerged. Although the different properties of tin doped indium oxide in the film form are interdependent, this article mainly focuses on the electrical aspects. Detailed description of the conduction mechanism and the main parameters that control the conductivity is presented. On account of the large varieties and differences in the fabrication techniques, the electrical properties of ITO films are discussed and compared within each technique.
876 citations
TL;DR: In this article, the authors reviewed the early stages of epitaxial growth and showed how the growth kinetics can be employed to create well-defined island morphologies and island arrays in a self-organization process.
851 citations
TL;DR: In this paper, transmission electron microscopy studies reveal that Ti, Ni and Pd coatings on the suspended tubes are continuous and quasi-continuous, resulting in nanotube-supported metal nanowire structures.
662 citations
TL;DR: In this paper, the shape transformation of gold nanorods in micellar solution by exposure to laser pulses of different pulse width (100 fs and 7 ns) and different energies (μJ to mJ) at 800 nm was studied.
Abstract: We studied the shape transformation (by use of TEM and optical absorption spectroscopy) of gold nanorods in micellar solution by exposure to laser pulses of different pulse width (100 fs and 7 ns) and different energies (μJ to mJ) at 800 nm, where the longitudinal surface plasmon oscillation of the nanorods absorb At moderate energies, the femtosecond irradiation melts the nanorods to near spherical particles of comparable volumes while the nanosecond pulses fragment them to smaller near-spherical particles At high energies, fragmentation is also observed for the femtosecond irradiation A mechanism involving the rate of energy deposition as compared to the rate of electron−phonon and phonon−phonon relaxation processes is proposed to determine the final fate of the laser-exposed nanorods, ie, melting or fragmentation
479 citations