scholarly journals Characterization of Uranium Particles Produced via Pulsed Laser Deposition

2003 ◽  
Vol 802 ◽  
Author(s):  
S. C. Glade ◽  
T. W. Trelenberg ◽  
J. G. Tobin ◽  
A. V. Hamza
Keyword(s):  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Scanning Tunneling Spectroscopy ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Gaseous Species ◽  
Experimental Apparatus

ABSTRACTWe have constructed an experimental apparatus for the synthesis (via pulsed laser deposition) and analysis of nanoparticles and thin films of plutonium and other actinides. In-situ analysis techniques include x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS). Also, the oxidation kinetics and the reaction kinetics of actinides with other gaseous species can be studied with this experimental apparatus. Preliminary results on depleted uranium are presented.

scholarly journals Oxidation of uranium nanoparticles produced via pulsed laser ablation

2005 ◽  
Vol 893 ◽  
Author(s):  
Tom Trelenberg ◽  
Stephen C Glade ◽  
James G Tobin ◽  
Thomas E Felter ◽  
Alex V Hamza
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Pulsed Laser ◽  
Scanning Tunneling ◽  
Residual Water ◽  
Tunneling Microscopy ◽  
Nanosecond Pulses ◽  
Langmuir Kinetics ◽  
Experimental Apparatus

AbstractAn experimental apparatus designed for the synthesis, via pulsed laser deposition, and analysis of metallic nanoparticles and thin films of plutonium and other actinides was tested on depleted uranium samples. Five nanosecond pulses from a Nd:YAG laser produced films of ∼1600 Å thickness that were deposited showing an angular distribution typical of thermal ablation. The films remained contiguous for many months in vacuum but blistered due to induced tensile stresses several days after exposure to air. The films were allowed to oxidize from the residual water vapor within the chamber (2×10-10 Torr base pressure). The oxidation was monitored by in-situ analysis techniques including x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and scanning tunneling microscopy (STM) and followed Langmuir kinetics.

Pulsed Laser Deposition and In Situ Scanning Tunneling Microscopy of Pd clusters supported on alumina

2011 ◽  
Vol 1351 ◽  
Author(s):  
C.S. Casari ◽  
S. Foglio ◽  
M. Corbetta ◽  
M. Passoni ◽  
C.E. Bottani ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Pulsed Laser Deposition ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Pd Clusters

ABSTRACTWith the aim of addressing the material gap issue between model and real systems in heterogeneous catalysis, we exploited Pulsed Laser Deposition (PLD) to produce Pd clusters supported on ultrathin alumina films (Pd/Al2O3/NiAl(001) and Pd/Al2O3-x/HOPG). The structural properties have been investigated by in situ Scanning Tunneling Microscopy (STM) in ultra high vacuum (UHV). At first, Pd clusters were deposited by evaporation and by PLD on Al2O3 surfaces grown by thermal oxidation of NiAl(001). The system shows thermal stability up to 650 K. By PLD we deposited Pd clusters with a good size control obtained by varying the background gas pressure and the target-to-substrate distance. We then realized aPd/Al2O3-x/HOPG system where both Pd clusters and the alumina film are produced by PLD showing that, by exploiting the same deposition technique, it is possible to synthesize both a model system addressable by in situ STM and a thick film (∼100 μm) closer to realistic systems.

Ultraviolet Assisted Pulsed Laser Deposition of Thin Oxide Films

1999 ◽  
Vol 574 ◽  
Author(s):  
V. Craciun ◽  
J. Howard ◽  
R. K. Singh
Keyword(s):  
Pulsed Laser Deposition ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Thin Layers ◽  
Laser Deposition ◽  
Gaseous Species ◽  
X Ray ◽  
Surface Mobility ◽  
Uv Illumination

AbstractThe properties of Y2O3, ITO (indium tin oxide), and TaSi2 thin layers grown using a new in-situ ultraviolet (UV)-assisted pulsed laser deposition (UVPLD) technique have been studied. X-ray diffraction investigations showed that with respect to conventional PLD grown films under similar conditions, but without UV illumination, UVPLD grown films exhibited better crystallinity, especially for growth at low substrate temperatures, from 200 °C up to 450 °C, depending on the material. X-ray photoelectron spectroscopy investigations showed that UVPLD layers contained less physisorbed oxygen than the conventional PLD layers, exhibiting a better overall stoichiometry. These results suggest that during the ablation-growth process, UV radiation increases the surface mobility of adatoms and provides more reactive gaseous species. Both factors contribute to the crystalline growth and are especially effective at moderate processing temperatures, where the thermal energy available for the process is comparatively low.

Epitaxial EuO thin films by pulsed laser deposition monitored by in situ x-ray photoelectron spectroscopy

2010 ◽  
Vol 518 (18) ◽  
pp. 5173-5176 ◽  
Author(s):  
J.N. Beukers ◽  
J.E. Kleibeuker ◽  
G. Koster ◽  
D.H.A. Blank ◽  
G. Rijnders ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray

Pulsed Laser Deposition of Cluster-Assembled Thin Films with Controlled Nanostructure

2005 ◽  
Vol 901 ◽  
Author(s):  
Andrea Li Bassi ◽  
Carlo Spartaco Casari ◽  
Fabio Di Fonzo ◽  
Alessandro Bailini ◽  
Matteo Fusi ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Film Surface ◽  
Specific Area ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Compact Structure ◽  
Background Gas

AbstractThin films synthesized by assembling clusters present interesting chemical and physical properties and a large specific surface, and are appealing for functional applications (e.g. sensing and catalysis). Also, clusters supported on surfaces are interesting both for nanocatalysis applications and for fundamental research. By means of pulsed laser deposition (PLD) in a background atmosphere we can induce cluster aggregation in the ablation plume and control the deposition kinetic energy of the clusters. These phenomena depend on the plume expansion dynamics and their influence on the properties of the deposited films has been investigated as a function of the background gas mass and pressure. The control of these parameters permits variation of the film surface morphology, from a compact structure with a very smooth surface, to a film with a controlled roughness at the nanoscale, to an open, low density meso- and nanostructure characterized by a high fraction of voids and by a large specific area. Thin films of WOx, TiOx, Pd/PdO, and Ag were deposited and characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy. Post-deposition annealing permits control of the crystalline degree of the films, which in the case of tungsten and titanium oxide is found to depend on the original nanostructure, while a different degree of oxidation can be induced by controlling the amount of oxygen in the deposition chamber. In-situ scanning tunneling microscopy (STM) was employed to study the first stages of growth of W films on different substrates. This opens the possibility to tailor the material properties through the control of the building nano-units.

In situ observation of atomic hydrogen etching on diamond-like carbon films produced by pulsed laser deposition

2001 ◽  
Vol 174 (3-4) ◽  
pp. 251-256 ◽  
Author(s):  
C.-L Cheng ◽  
C.-T Chia ◽  
C.-C Chiu ◽  
C.-C Wu ◽  
H.-F Cheng ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Atomic Hydrogen ◽  
Pulsed Laser ◽  
Carbon Films ◽  
Laser Deposition ◽  
Diamond Like Carbon ◽  
In Situ Observation ◽  
Hydrogen Etching
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