Navegação Ciências Exatas e da Terra por Autor "Papaleo, Ricardo Meurer"
Resultados 1-12 de 12
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Chemical damage in poly (phenylene sulphide) from fast ions: dependence on the primary-ion stopping power
(1996) [Artigo de periódico]Thin poly(phenylene sulphide) foils were bombarded with fast atomic ions (4He, 12C, 16O, 32S, 79Br, 127I) in the energy range between 2.5 to 78 MeV. In order to maintain the same ion track size for all impacting ions, their ... -
Confinement effects of ion tracks in ultrathin polymer films
(2015) [Artigo de periódico]We show direct experimental evidence that radiation effects produced by single MeV heavy ions on a polymer surface are weakened when the length of the ion track in the material is confined into layers of a few tens of ... -
Cratering and plastic deformation in polystyrene induced by MeV heavy ions : dependence on the molecular weight
(2001) [Artigo de periódico]Cratering and plastic deformation induced by individual MeV ions on the surface of polystyrene thin films of different molecular weights (Mw) (from 3250 to 2 X 10⁷u) are investigated using scanning force microscopy. 20 ... -
Cratering induced by slow highly charged ions on ultrathin PMMA films
(2022) [Artigo de periódico]Highly charged ions are a well-known tool for the nanostructuring of surfaces. We report on the thickness dependence of nanostructures produced by single 260 keV Xe38+ ions on ultrathin poly(methyl methacrylate) (PMMA) ... -
Diffusion reaction of oxigen in aluminum oxide films on silicon
(2002) [Artigo de periódico]Aluminum oxide films deposited on silicon by atomic layer chemical vapor deposition were annealed in an ¹⁸O-enriched oxygen atmosphere under various conditions of temperature, time, and pressure. Cavity formation at the ... -
Direct evidence for projectile charge-ctate dependent crater formation due to fast ions
(2008) [Artigo de periódico]We report on craters formed by individual 3 MeV/u Au qini⁺ ions of selected incident charge states qini penetrating thin layers of poly(methyl methacrylate). Holes and raised regions are formed around the region of the ... -
Formation of epitaxial [Beta]-Sn islands at the interface of SiO/sub 2/Si layers implanted with Sn ions
(2005) [Artigo de periódico]180 nm SiO2 layers on Si s100d were implanted with Sn ions producing a profile with a peak concentration of 3 at. % at the middle of the oxide. After high temperature s900–1100 °Cd annealing, an array of b-Sn islands ... -
Impact features induced by single fast ions of different charge-state on muscovite mica
(2021) [Artigo de periódico]The influence of the charge state q on surface modifications induced by the impact of individual fast, heavy ions on muscovite mica was investigated. Beams of 593 MeV 197Auq+ with well-defined initial charge states over a ... -
Low-mass secondary-ion ejection from molecular solids by mev heavy ions : radial velocity distributions
(1996) [Artigo de periódico]Secondary ions sputtered in individual MeV ion impacts are analyzed in a high resolution time-of-flight mass spectrometer. The initial radial velocity distributions of low mass (up to m/z≈300 u) positive and negative ... -
Measurement of MeV ion track structure in an organic solid
(1996) [Artigo de periódico]Radial velocities and effective ejection radii of hydrocarbon secondary ions sputtered electronically from polymer films have been experimentally determined. Using these data, the radial profiles of the energy and momentum ... -
Probing thermomechanical behavior of polymers at the nanometer scale with single-ion bombardment and scanning force microscopy
(2000) [Artigo de periódico]Features produced by swift heavy ions on polymer thin films at different temperatures are used to identify the transition between vitreous and viscoelastic behaviors (the glass transition temperature) and to probe the ... -
Ralaxation times of nanoscale deformations on the surface of a polymer thin film near and below the glass transition
(2006) [Artigo de periódico]We report on measurements of relaxation times of nanometer-sized deformations resulting from the impact of individual energetic ions on poly methyl methacrylate surfaces at temperatures close to and below the glass transition ...
