A5016588102- Ion-surface interactions and analysis
- Diamond and Carbon-based Materials Research
- Force Microscopy Techniques and Applications
- nanoparticles nucleation surface interactions
- Integrated Circuits and Semiconductor Failure Analysis
- Surface and Thin Film Phenomena
- Advanced Chemical Physics Studies
- Metal and Thin Film Mechanics
- Innovative Energy Harvesting Technologies
- Electron and X-Ray Spectroscopy Techniques
- Adhesion, Friction, and Surface Interactions
- Advanced Materials Characterization Techniques
- Superconducting and THz Device Technology
- Magnetic properties of thin films
- Theoretical and Computational Physics
- Mechanical and Optical Resonators
- Energy Harvesting in Wireless Networks
- Biomimetic flight and propulsion mechanisms
- Physics of Superconductivity and Magnetism
- Microfluidic and Capillary Electrophoresis Applications
- Near-Field Optical Microscopy
- Nanopore and Nanochannel Transport Studies
- Catalytic Processes in Materials Science
- Advanced Sensor and Energy Harvesting Materials
- Quantum and electron transport phenomena
University of Genoa
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2000-2023
National Interuniversity Consortium for the Physical Sciences of Matter
2007-2011
Georgia Institute of Technology
2004
École Polytechnique Fédérale de Lausanne
1994-2004
Istituto Nazionale per la Fisica della Materia
1994-2004
Surface etching by ion sputtering can be used to pattern surfaces. Recent studies using the high-spatial-resolution capability of scanning tunnelling microscope revealed in fact that bombardment produces repetitive structures at nanometre scale, creating peculiar surface morphologies ranging from self-affine patterns `fingerprint'-like and even regular structures, for instance waves (ripples), chequerboards or pyramids. The phenomenon is related interplay between erosion diffusion adatoms...
The morphology of the Ag(110) surface after ${\mathrm{Ar}}^{+}$ ion sputtering has been studied by a variable temperature scanning tunneling microscope. For energies greater than 800 eV and in range $270<{T}_{S}<320\mathrm{K}$ (where ${T}_{S}$ is temperature), peculiar ripple structure well aligned along $〈1\overline{1}0〉$ direction independent beam angle observed. A simple model this effect, based on anisotropy hierarchy Ag adatom vacancy diffusion, explains observed features.
The mechanism of strain relief for compressively stressed Ag layers epitaxially grown on Pt(111) is studied by scanning tunneling microscopy. in the compressed commensurate (1\ifmmode\times\else\texttimes\fi{}1) monolayer relieved bilayer formation two weakly incommensurate structures: metastable striped phase, which converts into a trigonal network domain walls upon annealing. This general case isotropic realized crossing walls. introduction phase shift one set allows system to account...
Nucleation has been studied on atomic scale for Ag deposition a Pt(111) surface at low temperature (50-120 K) by means of variable-temperature scanning tunneling microscopy. From island density versus coverage data, the transition from initial steps nucleation to growth and coalescence as function temperature. The data show that dimers are stable nuclei $T\ensuremath{\le}110$ K, which facilitates quantitative comparison with rate equations theory. migration barrier...
The European Research Council has recently funded HOLMES, a new experiment to directly measure the neutrino mass. HOLMES will perform calorimetric measurement of energy released in decay 163Ho. eliminates systematic uncertainties arising from use external beta sources, as experiments with spectrometers. This was proposed 1982 by A. De Rujula and M. Lusignoli, but only detector technological progress allowed design sensitive experiment. deploy large array low temperature microcalorimeters...
Surface morphology of a Cu(110) crystal, generated by ion sputtering, has been investigated scanning tunneling microscopy. Different from recent theoretical predictions and experimental results, normal sputtering produces well defined ripple structure whose wave vector rotates $〈001〉$ to $〈1\overline{1}0〉$ increasing the substrate temperature. Off-normal at low temperature (180 K) generates ripples orientation depends on both direction surface azimuthal orientation. These results are...
The evolution of the Cu(110) surface morphology during low temperature (180 K) ion sputtering was studied as a function incident beam angle $\ensuremath{\theta}$ by means scanning tunneling microscopy. dominated ripple structure with wave vector parallel or perpendicular to direction beam. time interface shows that wavelength increases in following scaling law $\ensuremath{\lambda}\ensuremath{\propto}{t}^{z}$,...
We present a critical view of the analysis experimental island densities acquired as function temperature in terms barriers and prefactors for tracer diffusion at surfaces. investigate achievable precision methods ranging from simple application scaling laws, via integration mean-field rate equations within various approximations capture rates, to kinetic Monte Carlo simulations that account shapes realized on square hexagonal lattices. The discussion theoretical models will be accompanied...
We investigated the dynamics of adsorption O2 on Ag(110) with molecular beam technique combined EEL spectroscopy and method King Wells. The initial sticking coefficient S0 is reported for molecules impinging along both high symmetry azimuthal directions 〈001〉 〈11̄0〉 as a function total energy angle incidence crystal temperature. anisotropic low well room temperature adsorption. dependence sample, Ts, indicates that takes place directly into well. Dissociation eventually induced thermally...
We have investigated the correlation between morphology and magnetic anisotropy in nanostructured Co films on Cu(001). The formation of nanoscale ripples by ion erosion is found to deeply affect properties film. A surface-type uniaxial with easy axis parallel observed. origin has been identified modification thermodynamic-step distribution induced ripple formation. At higher doses, when detach crystalline nanowires form, a strong enhancement due magnetostatic contributions
Surface etching by ion sputtering, besides producing equilibrium-oriented patterns similar to those obtained molecular beam epitaxy (MBE), can also be used pattern the surface along nonequilibrium orientations, thus extending possibilities of MBE. By tuning competition between erosion at grazing angles and diffusion-induced reorganization, it is, for example, possible a substrate characterized square symmetry with well-ordered ripple structure running any desired direction.
Here we report on the development of an unconventional approach for physical synthesis laterally ordered self-organized arrays metallic nanowires supported nanostructured dielectric templates. The method, based a combination nanoscale patterning glass substrate by ion beam sputtering with shadow deposition metal nanoparticles, provides viable alternative to time consuming serial nanopatterning approaches. Far-field optical characterization demonstrates that nanowire exhibit tunable...
We present a scanning tunneling microscopy study of the direct comparison between homoepitaxial deposition and surface ion sputtering on Ag(001) system. At temperature 200 K, results in mound formation similar to epitaxy case, while at higher temperatures an erosive regime sets with appearance regular square pits. Contrary conventional wisdom, which considers as vacancies, analysis single impact events reveals that process produces both adatom vacancy clusters. The key parameter determining...
We studied the dissociation of molecular oxygen adsorbed on Ag(110) by electron-energy-loss spectroscopy. observe that molecules at 150 K is connected to increased surface disorder. The elastic reflectivity recovered 200 independently coverage when added row reconstruction substrate sets in.
The chemisorption dynamics of ${\mathrm{O}}_{2}$ on Ag(110) was studied by molecular beams and high-resolution electron energy-loss spectroscopy measuring the initial sticking probability ${\mathit{S}}_{0}$ as a function translational energy ${\mathit{E}}_{\mathit{i}}$ angle incidence ${\mathrm{\ensuremath{\theta}}}_{\mathit{i}}$ along 〈001〉 〈11\ifmmode\bar\else\textasciimacron\fi{}0〉. $S sub 0--- scales ${\mathrm{cos}}^{\mathit{n}}$${\mathrm{\ensuremath{\theta}}}_{\mathit{i}}$ with n=1.1...
The controlled production of nanostructures endowed with well-selected shapes and reduced dimensionality represents a multidisciplinary key activity in nanotechnology. In particular, great effort is currently oriented at the development metal nanoparticle arrays order to exploit strong field-enhancement effects associated excitation localized surface plasmon resonances. Here we demonstrate that ion-beam sputtering can be successfully employed convert polycrystalline film into disconnected...
We report on self-organized patterning of polycrystalline noble metal films, supported dielectric substrates, by defocused Ar+ ion beam irradiation. The initial surface morphology affects the formation nanostructures, forcing growth ripples with a lateral periodicity imposed pristine grain distribution. At early stages, self-organization process is dominated shadowing taller grains, while crossover to conventional erosive regime, observed for single crystals, sets in at longer sputtering...
In this Letter, we present and discuss an energy harvesting device, based on a wing elastically bounded to fixed support. Large amplitude periodic oscillations can be induced when system is subject wind, if few parameters are carefully set. A linear stability analysis as well two-dimensional numerical simulations confirms the existence of instability regions in parameter space. order harvest by using system, different methods considered. Preliminary results obtained electromagnetic coupling...
Using atomic force microscopy and spot-profile analyzing low energy electron diffraction, we have observed the existence of a striking faceting instability in Al(110) homoepitaxy, characterized by formation nanocrystals with well-defined facets. These hut-shaped are over tenfold higher than total film coverage, coexist bimodal growth mode much shallower more populous surface mounds. We further use density functional theory calculations to elucidate microscopic origin instability, induced...