Optical properties of nanocomposites with iron core–iron oxide shell structure

Basu, Soumen; Chakravorty, D.

doi:10.1016/j.jnoncrysol.2006.01.006

Cited by 37 publications

(19 citation statements)

References 24 publications

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“…Multiconstituent nanostructures have recently attracted much attention, from both the experimental and theoretical points of view, since it is possible to obtain dramatic changes in chemical, 1-5 magnetic, 6,7 and optical properties [8][9][10] compared to those of the individual metals. Indeed, bimetallic clusters represent a large family of constructors where both the size and the chemical composition play a significant role in their structures and thus in their chemical and physical properties.…”

Section: Introductionmentioning

confidence: 99%

Superficial segregation, wetting, and dynamical equilibrium in bimetallic clusters: A Monte Carlo study

et al. 2008

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Using Monte Carlo simulations on a lattice-gas model within the pseudo-grand-canonical ensemble, we study the competition between superficial segregation, wetting and a core dynamical equilibrium for nanoparticles made of thousands of atoms in a system that tends to phase separate, e.g., Cu-Ag. Increasing the chemical potential difference ⌬ between Ag and Cu ͑or the nominal Ag concentration͒ at a temperature lower than the critical temperature for the phase separation in the infinite crystal, we show that the cluster goes through different stages: ͑i͒ Ag-superficial segregation that involves the vertices first, then the edges, and finally the ͑111͒ and ͑001͒ facets; ͑ii͒ prewetting that leads to Ag enrichment on the shells close to the cluster surface; ͑iii͒ a dynamical equilibrium that affects all the internal shells jointly, similar to the first-order phase transition due to the miscibility gap in an infinite crystal; and ͑iv͒ again standard segregation. Moreover, we show that a similar behavior occurs for the cluster facets if the temperature is lower than the critical temperatures of the first-order phase transition of the corresponding surfaces of semi-infinite crystals. A remarkable consequence of those dynamical equilibria is that very different concentrations of the facets on one hand and of the whole cluster on the other hand can be observed at a given ⌬.

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Section: Introductionmentioning

confidence: 99%

Superficial segregation, wetting, and dynamical equilibrium in bimetallic clusters: A Monte Carlo study

et al. 2008

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“…[19] Siwach and Sen [20] reported a narrow peak at 264 nm and a broad peak at 352 nm for iron nanoparticles prepared through the technique of electro-exploding wire, and they assigned the peak at 264 nm to a discrete electronic transition in iron nanoparticles and the peak at 352 to remnants of collective oscillation of the surface electrons such as surface plasmons. [20] Other reports of UV absorbance spectra for Fe nanoparticles are similar: a broad UV absorption of 300-350 nm of Basu and Chakravorty [21] and two peaks at 262 and 352 nm of Klacanova et al [22] It is significant that all these papers reported a similar peak in the range of 350-360 nm as characteristic of iron nanoparticles. [20] The difference between the reported UV absorption spectra is probably due to the different surfaces of their iron nanoparticles as prepared by different synthetic techniques.…”

Section: Resultsmentioning

confidence: 86%

Silicon nanoparticles synthesised through reactive high-energy ball milling: enhancement of optical properties from the removal of iron impurities

Kuang

Mitchell

Fink

2014

Journal of Experimental Nanoscience

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Alkyl-terminated silicon nanoparticles (SiNPs) were prepared through reactive high-energy ball milling with contamination of iron from the steel milling materials. Iron impurities in the form of iron nanoparticles cause a decrease of photoluminescence intensity and an increase of the UV absorption. The iron impurities were removed either by gel permeation chromatography separation or by treatment with an aqueous HCl solution. The photoluminescence properties of the SiNPs were enhanced after the removal of iron. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and proton nuclear magnetic resonance were used to determine morphology, elemental composition and surface passivation of SiNPs.

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“…This absorption peak is the signature of the existence of Fe NPs and is due to their localized surface plasmon resonance. [42][43][44] Samples #1 and #2 exhibit sharper peaks compared to #3 and #4 with wide peaks and a small red shift as a function of Fe/C content. This 10 occurs because of change in size and distribution of NPs 1 , which is confirmed by AFM images.…”

Section: Discussionmentioning

confidence: 99%

Microstructure and Tribological Properties of FeNPs@a-C:H Films by Micromorphology Analysis and Fractal Geometry

Ţălu

Bramowicz

Kulesza

et al. 2015

Ind. Eng. Chem. Res.

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This paper analyses the three-dimensional (3-D) surface texture of amorphous hydrogenated carbon films with sputtered iron nanoparticles (Fe NPs @ a-C: H) deposited by RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) method on the quartz substrates. The prepared Fe NPs @ a-C: H films were used as research materials. The synthesized samples were deposited at four different pressures of 2.5, 3, 3.35 and 3.5 N/m 2 in the acetylene gas atmosphere. The Fe and C content of the thin films was obtained from X-ray photoelectron spectroscopy (XPS). X-ray diffraction profile and electron diffraction pattern indicates that iron nanoparticles with body-centered cubic crystalline structure are formed in these films. Localized Surface Plasmon Resonance (LSPR) peak that is signature of the existence of the Fe core nanoparticles appears in visible spectra of these films. The sample surface images were recorded using an Atomic Force Microscope (AFM) operating in a non-contact mode and analyzed to reveal statistical, fractal and functional surface properties of prepared samples. The analysis of 3-D surface texture is essential for the correct interpretation of surface topographic features as well as its functional role for the test surface. It also helps to understand the relationship between the surface topography and the functional properties.

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Optical properties of nanocomposites with iron core–iron oxide shell structure

Cited by 37 publications

References 24 publications

Superficial segregation, wetting, and dynamical equilibrium in bimetallic clusters: A Monte Carlo study

Superficial segregation, wetting, and dynamical equilibrium in bimetallic clusters: A Monte Carlo study

Silicon nanoparticles synthesised through reactive high-energy ball milling: enhancement of optical properties from the removal of iron impurities

Microstructure and Tribological Properties of FeNPs@a-C:H Films by Micromorphology Analysis and Fractal Geometry

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