Low-Loss EELS Study of Oxide-Covered Aluminum Nanospheres

Stöckli, Thomas; Stadelmann, PA; Châtelain, A.

doi:10.1051/mmm:1997113

Cited by 14 publications

(6 citation statements)

References 17 publications

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“…Comparing the ϩ plasmon resonance energy close to the center of different size particles it can be noticed that the resonance is shifted to lower energies as the spheres become smaller. This is in contradiction to what is observed in the case of small metallic particles [48][49][50] where the volume plasmon resonance energy has tendency to rise to higher values. In the case of metallic particles, this blueshift is ascribed to the effect of dispersion in a finite medium.…”

Section: B Size Dependence and Particular Featurescontrasting

confidence: 99%

Plasmon excitations in graphitic carbon spheres measured by EELS

et al. 2000

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The determination of the physical properties of individual nanometer-size particles has made rapid progress with the availability of local probe techniques during the past years. Electron energy-loss spectroscopy in a high-resolution transmission electron microscope is one experimental tool that can give insight into the intriguing properties of such small particles. The interpretation of the experimental data of the plasmon excitations is well established in the case of isotropic particles of different geometries. For the case of anisotropic particles such as multiwall fullerenes ͑carbon onions͒, the interpretation schemes had to be reviewed. In a recent publication, we have proposed a formalism based on nonrelativistic local dielectric response theory for high-energy transmission electron microscopy electrons penetrating or passing close by an anisotropic particle ͓Stöckli et al., Phys. Rev. B 57, 15599 ͑1998͔͒. Here we report a detailed comparison of experimental data with the excitation probabilities obtained within this formalism. We show that there is an excellent agreement between theory and experiment. In consequence, we are able to interpret the plasmon loss data of multiwall fullerenes and draw conclusions on their physical properties.

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Section: B Size Dependence and Particular Featurescontrasting

confidence: 99%

Plasmon excitations in graphitic carbon spheres measured by EELS

et al. 2000

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“…Models developed within the frame of classical dielectric response theory 34 have been used with success to interpret plasmon losses in electron energy loss spectroscopy. Such models predict correctly the resonance energies and the intensities of the surface and volume plasmon excitations for different geometries such as thin slabs, 35 spheres, [36][37][38][39] layered spheres, 38,40,41 spheres halfway embedded in a supporting medium, 42,43 and cylindrical channels [44][45][46][47] and explain size-dependent variations of the peak position. The electronic properties of the material composing the nanoparticle are taken into account via its frequency-dependent dielectric function.…”

Section: Introductionmentioning

confidence: 99%

Plasmon excitations in graphitic carbon spheres

et al. 1998

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Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In the plasmon region, the experimental data reveal interesting size-dependent variations, which are not yet fully understood. The difficulties encountered in the interpretation of the spectra are principally due to the lack of a complete theoretical treatment of the anisotropic dielectric response in nanometer-size particles. In order to obtain a better understanding of the experimental data we propose a model based on nonrelativistic local dielectric response theory for electrons penetrating through a nested concentric-shell fullerene or the so-called ''carbon onion.'' The anisotropy of the electronic properties of the sphere is taken into account via the frequency-dependent dielectric tensor of graphite. The model can be applied to simulate electron energy loss spectra as well as line scans through energy filtered images and allows thus a direct comparison to experimental data. ͓S0163-1829͑98͒04724-9͔

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“…A shift to lower energy is expected at the interface with an oxide, as observed at planar interfaces 8,9 as well as nanostructure-oxide interfaces. [10][11][12] The condition for resonance at planar interfaces between two materials A and B is 1A ()ϩ 1B ()ϭ0. 1 While the dielectric functions for the bismuth nanowires and templates have not been determined, 5.5 eV is a reasonable energy to expect for an interface plasmon based on the bismuth 21 and alumina 22 bulk values.…”

Section: Resultsmentioning

confidence: 99%

“…Studies of plasmons at planar interfaces and at nanoparticle interfaces have been used to assess interfacial chemistry and properties. [8][9][10][11][12] By coupling an EELS spectrometer with the powerful imaging capabilities of the TEM, it is also possible to select those electrons that have undergone a specific loss event during their transit through the sample and display the spatial variation of that loss event in an image. Such ''energy-filtered imaging'' of the plasmon excitations can be used to identify those regions of the sample that sustain a plasmon mode.…”

Section: Introductionmentioning

confidence: 99%

Plasmon excitation modes in nanowire arrays

Sander

Gronsky

Lin

et al. 2001

Journal of Applied Physics

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Electron energy loss spectrometry and energy-filtered transmission electron microscopy reveal characteristic plasmon excitations in both isolated Bi nanowires and an array of Bi nanowires within an Al 2 O 3 matrix. As the average nanowire diameter decreases from 90 to 35 nm, both the volume plasmon energy and peak width increase. In addition, a lower-energy excitation is present in a very localized region at the Bi-Al 2 O 3 interface. These results are discussed in the context of quantum confinement and the influence of interfaces on the electronic properties of nanocomposite materials.

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Low-Loss EELS Study of Oxide-Covered Aluminum Nanospheres

Cited by 14 publications

References 17 publications

Plasmon excitations in graphitic carbon spheres measured by EELS

Plasmon excitations in graphitic carbon spheres measured by EELS

Plasmon excitations in graphitic carbon spheres

Plasmon excitation modes in nanowire arrays

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