Engineering the Optical Properties of Gold Nanorods: Independent Tuning of Surface Plasmon Energy, Extinction Coefficient, and Scattering Cross Section

2014 ◽  
Vol 118 (11) ◽  
pp. 5918-5926 ◽  
Author(s):  
Kyoungweon Park ◽  
Sushmita Biswas ◽  
Sushil Kanel ◽  
Dhriti Nepal ◽  
Richard A. Vaia
Keyword(s):  
Optical Properties ◽  
Cross Section ◽  
Surface Plasmon ◽  
Gold Nanorods ◽  
Extinction Coefficient ◽  
Scattering Cross Section ◽  
Plasmon Energy ◽  
Scattering Cross

scholarly journals Theory underpinning multislice simulations with plasmon energy losses

Microscopy ◽  
2020 ◽  
Vol 69 (3) ◽  
pp. 173-175
Author(s):  
B G Mendis
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Monte Carlo Methods ◽  
Bloch Wave ◽  
Incident Electron ◽  
Scattering Cross Section ◽  
Energy Losses ◽  
Plasmon Energy ◽  
Scattering Cross ◽  
Wave Nature

Abstract The theoretical conditions for small-angle inelastic scattering where the incident electron can effectively be treated as a particle moving in a uniform potential is examined. The motivation for this work is the recent development of a multislice method that combines plasmon energy losses with elastic scattering using Monte Carlo methods. Since plasmon excitation is delocalized, it was assumed that the Bloch wave nature of the incident electron in the crystal does not affect the scattering cross-section. It is shown here that for a delocalized excitation the mixed dynamic form factor term of the scattering cross-section is zero and the scattered intensities follow a Poisson distribution. These features are characteristic of particle-like scattering and validate the use of Monte Carlo methods to model plasmon losses in multislice simulations.

Tunable optical properties of silver–dielectric–silver nanoshell

2014 ◽  
Vol 28 (20) ◽  
pp. 1450134 ◽  
Author(s):  
Farzad Shirzaditabar ◽  
Maryam Saliminasab
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Cross Section ◽  
Resonance Wavelength ◽  
Scattering Cross Section ◽  
Core Radius ◽  
Dielectric Thickness ◽  
Scattering Cross ◽  
Tunable Optical Properties ◽  
Silver Core

Tunable optical properties of silver–dielectric–silver nanoshell including surface plasmon resonance (SPR) and resonance light scattering (RLS) based on quasi-static theory are investigated. When the silver core radius increases, the longer resonance wavelength red shifts and light scattering cross-section decreases whereas the shorter resonance wavelength blue shifts and the light scattering cross-section increases. The effect of middle dielectric thickness on the light scattering cross-section of nanoshell is different from those of the silver core radius changes. As middle dielectric radius increases, the longer resonance wavelength first blue shifts and then red shifts and the light scattering cross-section increases whereas the shorter resonance wavelength always red shifts and the light scattering cross-section decreases. The sensitivity of RLS to the refractive index of embedding medium is also reported. As the silver core radius increases, the sensitivity of silver–dielectric–silver nanoshell decreases whereas increasing the middle dielectric thickness leads to increase the sensitivity of silver–dielectric–silver nanoshell. Tunable optical properties of silver–dielectric–silver nanoshell verify the biosensing potential of this nanostructure.

scholarly journals Effects of the Fractal Prefactor on the Optical Properties of Fractal Soot Aggregates

2009 ◽  
Author(s):  
Fengshan Liu ◽  
David R. Snelling ◽  
Gregory J. Smallwood
Keyword(s):  
Optical Properties ◽  
Fractal Dimension ◽  
Cross Section ◽  
Laser Wavelength ◽  
Scattering Cross Section ◽  
Differential Scattering Cross Section ◽  
Scattering Cross ◽  
Primary Particles ◽  
Total Scattering Cross Section ◽  
The Difference

The effects of prefactor on the optical properties of numerically generated fractal soot aggregates were investigated using the numerically exact generalized multi-sphere Mie-solution method (GMM) and the approximate Rayleigh-Debye-Gans (RDG) theory. The numerically generated fractal aggregates consist of 50 to 400 primary particles of 30 nm in diameter. The considered incident laser wavelength is 266 nm. Attention is paid to the effect of prefactor on the vertical-vertical differential scattering cross section, since such quantity has often been used to infer the fractal dimension and prefactor based on the RDG formulation. The fractal prefactor affects the optical properties of the numerically generated soot aggregates through its influence on the compactness of the structure. Using GMM to calculate the optical properties of the numerically generated aggregates results in a lower aggregate absorption cross section, but a higher total scattering cross section with increasing the prefactor. The difference between the RDG results and those of GMM is primarily caused by multiple scattering and such effect is found significant, especially for the higher value of prefactor considered. The fractal dimension derived from the GMM non-dimensional differential scattering cross section agrees well with the morphological value in the case of the lower prefactor of 1.3 considered; however, the derived fractal dimension is much higher than the morphological value for fractal soot aggregates with a prefactor of 2.3. The light scattering derived prefactor is in general lower than the morphological value, especially when the morphological prefactor is higher.

scholarly journals Two dimensional dipolar coupling in monolayers of silver and gold nanoparticles on a dielectric substrate

Nanoscale ◽  
2014 ◽  
Vol 6 (20) ◽  
pp. 12080-12088 ◽  
Author(s):  
Yu Liu ◽  
Sylvie Begin-Colin ◽  
Benoît P. Pichon ◽  
Cedric Leuvrey ◽  
Dris Ihiawakrim ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cross Section ◽  
Surface Plasmon ◽  
Dipolar Coupling ◽  
Three Dimensional ◽  
Dielectric Substrate ◽  
Scattering Cross Section ◽  
Two Dimensional ◽  
Silver And Gold Nanoparticles ◽  
Scattering Cross

This work reports about nanoparticle dipolar effects and substrate to nanoparticle interaction by modeling the surface plasmon scattering cross-section on experimental two dimensional monolayers versus three dimensional randomly distributed assemblies.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

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