Dispersion Properties of High- and Low-Frequency Electrostatic Oscillations of Plasma Spheres: Application to the Metallic Nanoparticles

2015 ◽  
Vol 64 (5) ◽  
pp. 571-575 ◽  
Author(s):  
Afshin Moradi
Keyword(s):  
Metallic Nanoparticles ◽  
Low Frequency ◽  
Dispersion Properties

SYNTHESIS OF ALLOY METAL NANOCLUSTERS IN SILICA GLASS BY SEQUENTIAL ION IMPLANTATION

2007 ◽  
Vol 06 (06) ◽  
pp. 423-430 ◽  
Author(s):  
B. JOSEPH ◽  
H. P. LENKA ◽  
P. K. KUIRI ◽  
D. P. MAHAPATRA ◽  
R. KESAVAMOORTHY
Keyword(s):  
Ion Implantation ◽  
Silica Glass ◽  
Metallic Nanoparticles ◽  
Rutherford Backscattering Spectrometry ◽  
Low Frequency ◽  
Peak Position ◽  
Negative Ion ◽  
Metal Nanoclusters ◽  
Cross Sectional ◽  
The Matrix

High fluence low energy negative ion implantation has been used to synthesize embedded metal nanoclusters of Au , Ag and Sb in silica glass. The Au - and Ag -implanted samples showed peaks, corresponding to surface plasmon resonance (SPR) in the optical absorption (OA) spectra, confirming the formation of metallic nanoparticles in the matrix. No SPR peak was observed in case of Sb -implanted samples which is attributed to the absence of pure metallic precipitates which could be detected in the OA spectrum. Low frequency Raman scattering (LFRS) measurements also confirm this. Cross-sectional transmission electron microscopy has been used to infer about the size distribution of the nanoparticles. Sequential implantations of Au and Ag or Au and Sb have been found to result in SPR peaks at locations in between those for nanoparticles of the constituent atoms, indicating the formation of alloy nanoparticles in the system. In case of the Au + Ag system, Rutherford backscattering spectrometry has been used to infer about the composition of the nanoparticles in terms of the concentrations of the metallic constituents. A direct, one-to-one correspondence between the SPR peak position and composition has been observed.

Low-frequency negative capacitance effect in systems of metallic nanoparticles embedded in dielectric matrix

2004 ◽  
Vol 85 (2) ◽  
pp. 302-304 ◽  
Author(s):  
G. B. Parravicini ◽  
A. Stella ◽  
M. C. Ungureanu ◽  
R. Kofman
Keyword(s):  
Metallic Nanoparticles ◽  
Low Frequency ◽  
Negative Capacitance ◽  
Dielectric Matrix ◽  
Capacitance Effect

Low-frequency dispersion properties of plasmas with variable-charge impurities

2000 ◽  
Vol 7 (2) ◽  
pp. 461-465 ◽  
Author(s):  
K. N. Ostrikov ◽  
S. V. Vladimirov ◽  
M. Y. Yu ◽  
G. E. Morfill
Keyword(s):  
Low Frequency ◽  
Frequency Dispersion ◽  
Dispersion Properties ◽  
Variable Charge

scholarly journals Identification of Buffer and Surface Traps in Fe-Doped AlGaN/GaN HEMTs Using Y21 Frequency Dispersion Properties

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3096
Author(s):  
P. Vigneshwara Raja ◽  
Nandha Kumar Subramani ◽  
Florent Gaillard ◽  
Mohamed Bouslama ◽  
Raphaël Sommet ◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Dispersion ◽  
Drain Current ◽  
Surface Region ◽  
Electron Trap ◽  
High Electron ◽  
Trap States ◽  
Dispersion Properties ◽  
Donor States ◽  
Surface Donor

The buffer and surface trapping effects on low-frequency (LF) Y-parameters of Fe-doped AlGaN/GaN high-electron mobility transistors (HEMTs) are analyzed through experimental and simulation studies. The drain current transient (DCT) characterization is also carried out to complement the trapping investigation. The Y22 and DCT measurements reveal the presence of an electron trap at 0.45–0.5 eV in the HEMT structure. On the other hand, two electron trap states at 0.2 eV and 0.45 eV are identified from the LF Y21 dispersion properties of the same device. The Y-parameter simulations are performed in Sentaurus TCAD in order to detect the spatial location of the traps. As an effective approach, physics-based TCAD models are calibrated by matching the simulated I-V with the measured DC data. The effect of surface donor energy level and trap density on the two-dimensional electron gas (2DEG) density is examined. The validated Y21 simulation results indicate the existence of both acceptor-like traps at EC –0.45 eV in the GaN buffer and surface donor states at EC –0.2 eV in the GaN/nitride interface. Thus, it is shown that LF Y21 characteristics could help in differentiating the defects present in the buffer and surface region, while the DCT and Y22 are mostly sensitive to the buffer traps.

scholarly journals Low-frequency electrostatic wave in a metallic electron-hole-ion plasma with nanoparticles

2009 ◽  
Vol 75 (5) ◽  
pp. 581-585
Author(s):  
P. K. SHUKLA ◽  
G. E. MORFILL
Keyword(s):  
Metallic Nanoparticles ◽  
Low Frequency ◽  
Dispersion Property ◽  
Charged Dust ◽  
Number Density ◽  
Electron Hole ◽  
Electrostatic Wave ◽  
Quantum Hydrodynamic Model ◽  
Ion Plasma ◽  
Density Perturbations

AbstractWe investigate the dispersion property of a low-frequency electrostatic wave in a dense metallic electron-hole-ion plasma with nanoparticles. The latter are charged due to the field emission, and hence the metallic nanoparticles/nanotubes can be regarded as charged dust rods surrounded by degenerate electrons and holes, and non-degenerate ions. By using a quantum hydrodynamic model for the electrons and holes, we obtain the electron and hole number density perturbations, while the ion and dust rod number density perturbations follow the classical expressions. A dispersion relation for the low-frequency electrostatic wave in our multi-species dense metallic plasma is derived and analyzed. The possibility of exciting non-thermal electrostatic waves is also discussed.

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