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Author

D. Ila

Bio: D. Ila is an academic researcher from Texas A&M University. The author has contributed to research in topics: Ion implantation & Rutherford backscattering spectrometry. The author has an hindex of 15, co-authored 135 publications receiving 777 citations.


Papers
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Journal ArticleDOI
TL;DR: A mercury sorbent test was performed near the headwaters of the Upper East Fork Poplar Creek at the Oak Ridge Y-12 Plant in Tennessee and the sorbents SIR-200, Keyle:X, and GT-73 were the best materials tested for low level mercury removal.

33 citations

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TL;DR: In this paper, the authors reported the results of characterization of nonlinear refractive index of the composite material produced by MeV Ag ion implantation of LiNbO(sub 3) crystal (z-cut).
Abstract: We report the results of characterization of nonlinear refractive index of the composite material produced by MeV Ag ion implantation of LiNbO(sub 3) crystal (z-cut). The material after implantation exhibited a linear optical absorption spectrum with the surface plasmon peak near 430 nm attributed to the colloidal silver nanoclusters. Heat treatment of the material at 500 deg C caused a shift of the absorption peak to 550 nm. The nonlinear refractive index of the sample after heat treatment was measured in the region of the absorption peak with the Z-scan technique using a tunable picosecond laser source (4.5 ps pulse width).The experimental data were compared against the reference sample made of MeV Cu implanted silica with the absorption peak in the same region. The nonlinear index of the Ag implanted LiNbO(sub 3) sample produced at five times less fluence is on average two times greater than that of the reference.

30 citations

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TL;DR: In this article, the authors used the energy deposited due to the electronic excitation by post-implantation irradiation to induce the nucleation of nano-clusters of Au in silica.
Abstract: We have used the energy deposited due to the electronic excitation by post-implantation irradiation to induce the nucleation of nano-clusters of Au in silica. We have produced the Au/silica by two methods. (A) MeV Au implantation into silica, (B) producing thin films of a combined Au and silica on a silica substrate, using co-deposition of gold and silica. The process of ion beam assisted nucleation of nano-clusters was used to reduce the threshold implantation dose, or the Au concentration in the silica host, required to produce Au nano-crystals by at least two orders of magnitude. In this presentation, we applied a similar technique, post-irradiation electronic excitation, to films produced by both ion implantation of Au into silica as well as to films produced using co-deposition of gold and silica. By a co-deposition technique, gold and silica (co-deposited at various concentrations) are grown, then post-irradiated. The resultant Au nano-cluster formation was observed and studied using optical spectroscopy, X-ray diffraction, RBS and TEM.

27 citations

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TL;DR: In this article, it was shown that a 3-MeV proton fluence as small as 2.28×1013mm−2 statistically reduces the ZnS:Mn decay time for temperatures less than 200°C.
Abstract: Research has shown that the fluorescence decay time can be used to measure temperatures in adverse environments, such as those found in space. Development of space-based phosphor sensors will depend heavily upon research investigating the resistance of phosphors to ionizing radiation. Research completed at the Alabama A&M University Center for Irradiation of Materials (CIM) shows that a 3 MeV proton fluence as small as 2.28 × 1013 mm−2 statistically reduces the ZnS:Mn decay time for temperatures less than 200 °C. Reductions in decay time appear to be proportional to increasing 3 MeV proton fluence beyond 2.28 × 1013 mm−2. It is possible that radiation induced dislocations in ZnS:Mn or the formation of sooty carbon in the binder could account for some of these reductions.

27 citations

Journal ArticleDOI
TL;DR: In this paper, the authors show how and at what concentrations species such as gold nucleates to form nanoclusters, either by induced strain or by radiation-enhanced nucleation at a dose below that needed for spontaneous nanocluster formation.
Abstract: There is a threshold implantation dose, after which some of the implanted species will tend to spontaneously form nanoclusters, over-dose-implantation . Similarly, there is a threshold implantation dose for the implanted species in a layer of the host material, such that after high temperature annealing the nanoclusters can nucleate before the implanted material can dissolve in the host material (during such heat treatments). In this paper, we present the results of our investigation of producing nanoclusters of gold in silica at fluences of two orders of magnitude less than what is traditionally used. This is accomplished by implanting 2.0 MeV Au into silica followed by MeV bombardment by MeV Si ions. This process was used to reduce the threshold implantation dose by at least two orders of magnitude. To follow the formation of nanoclusters, we used both indirect measurement methods such as optical absorption spectrophotometry (non-destructive), and direct methods such as transmission electron microscopy (destructive). The size of the nanoclusters, ranging from 1 to 10 nm, are controlled by the implantation dose and by the total electronic energy deposited by each post-bombarding ion in the implanted layer. We will show how and at what concentrations species such as gold nucleates to form nanoclusters, either by induced strain or by radiation-enhanced nucleation at a dose below that needed for spontaneous nanocluster formation.

26 citations


Cited by
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TL;DR: A review of gold nanoparticles can be found in this article, where the most stable metal nanoparticles, called gold colloids (AuNPs), have been used for catalysis and biology applications.
Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

11,752 citations

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TL;DR: In this article, the authors review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes.
Abstract: A common misconception is that the irradiation of solids with energetic electrons and ions has exclusively detrimental effects on the properties of target materials. In addition to the well-known cases of doping of bulk semiconductors and ion beam nitriding of steels, recent experiments show that irradiation can also have beneficial effects on nanostructured systems. Electron or ion beams may serve as tools to synthesize nanoclusters and nanowires, change their morphology in a controllable manner, and tailor their mechanical, electronic, and even magnetic properties. Harnessing irradiation as a tool for modifying material properties at the nanoscale requires having the full microscopic picture of defect production and annealing in nanotargets. In this article, we review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes. We also consider the t...

905 citations

Journal Article
TL;DR: The initial stages of the interaction of oxygen gas with a clean Ni surface have been studied by a combination of LEED, AES, work function change and ion bombardment sectioning techniques as discussed by the authors.

387 citations

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TL;DR: In this paper, AgNPs with approximately 15nm in diameter were attached to the surface of polyamide thin-film composite (TFC) membrane via covalent bonding, with cysteamine as a bridging agent.

312 citations

Journal ArticleDOI
TL;DR: In this paper, a broad overview of thermographic phosphor film preparation techniques is presented and an entire error analysis is given for this technique, which may sensitise future studies for error sources and encourage an estimation of their total accuracy.

292 citations