Plasmon Line Widths of Single Silver Nanoprisms as a Function of Particle Size and Plasmon Peak Position

2007 ◽  
Vol 111 (51) ◽  
pp. 18906-18911 ◽  
Author(s):  
Keiko Munechika ◽  
Jessica M. Smith ◽  
Yeechi Chen ◽  
David S. Ginger
Keyword(s):  
Particle Size ◽  
Peak Position ◽  
Silver Nanoprisms ◽  
Plasmon Peak ◽  
Line Widths

scholarly journals Structural Study of the Photo-Mediated Growth of Silver Nanoprisms

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5413
Author(s):  
Matti Knaapila ◽  
Ulla Vainio ◽  
Sophie E. Canton ◽  
Gunnel Karlsson
Keyword(s):  
Particle Size ◽  
Small Angle ◽  
Volume Ratio ◽  
Direct Methods ◽  
Saxs Data ◽  
Aqueous Dispersions ◽  
X Ray ◽  
Silver Nanoprisms ◽  
X Ray Scattering ◽  
Ag Particles

We present a small-angle X-ray scattering (SAXS) study of the anisotropic photoinduced growth of silver (Ag) nanoprisms in aqueous dispersions. The growth of nearly spherical (<10 nm) Ag particles into large (>40 nm) and thin (<10 nm) triangular nanoprisms induced by 550 nm laser is followed in terms of particle size using indirect and direct methods for irradiation times up to 150 min. During the process, the surface-to-volume ratio of the particles decreased. The SAXS data of the initial solution fit well to the model of polydisperse spheres with pronounced average diameters around 7.4 nm and 10 nm. The data after 45 min irradiation fit well to the model containing approximately the same amount of the initial particles and the end product, the nanoprisms.

The Influence of the Peptide Molar Ratios on the Functionalization of Gold Nanoparticles

2013 ◽  
Vol 872 ◽  
pp. 94-105
Author(s):  
Mayra C. Ramirez-Camacho ◽  
Inga Tuzovskaya ◽  
Nina Bogdanchikova ◽  
Alexey Pestryakov ◽  
Arturo Susarrey-Arce ◽  
...  
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Sodium Citrate ◽  
Red Shift ◽  
Molar Ratio ◽  
Narrow Particle Size Distribution ◽  
Plasmon Peak ◽  
Vis Spectroscopy

Au nanoparticles (NPs) functionalized with L-cysteine (Cys) and cysteine-glycine (Cys-Gly) were synthetized. The AuNPs were prepared using sodium citrate as reducing agent. The influence of the molar concentrations of Cys and Cys-Gly, as well as the sodium citrate is studied on particle size and particle size distribution. TEM measurements revealed the formation of AuNPs with diameter in the range 5-35 nm which corresponds to nontoxic sizes [we should add a reference here, perhaps number one]. The optimal particle size for biomedical application along with narrow particle size distribution was observed for samples prepared with molar ratio of CAu:Ccitrate = 1:10. The results of UV-Vis spectroscopy revealed the interaction of the AuNPs with Cys and Gly-Cys demonstrated by a visible change in the absorption intensities of the plasmon peak located at 520 nm after AuNP functionalization and a slight shifting of this gold nanoparticles plasmon peak. Thus, any dielectric shell on surface of particles with more refraction index (and, correspondingly, dielectric function) can produce the particles with the red shift. Such effect of the surface shell with red-shift in the range of few nanometers observed for the AuNPs functionalized with Cys and Cys-Gly (Fig. 4) can be interpreted as thin or discontinuous layer of aminoacid molecules according to the data of optical spectra simulation.

Changes in plasmon peak position in a GaAs/Tn0.2Ga0.8As structure

2006 ◽  
pp. 163-166
Author(s):  
R Beanland ◽  
A M Sánchez ◽  
A J Papworth ◽  
M H Gass ◽  
P J Goodhew
Keyword(s):  
Peak Position ◽  
Plasmon Peak

Surface Plasmon Resonance in Nanocrystalline Gold–Copper Alloy Films

2007 ◽  
Vol 7 (12) ◽  
pp. 4486-4493 ◽  
Author(s):  
S. Hussain ◽  
Subhadeep Datta ◽  
R. K. Roy ◽  
A. K. Pal
Keyword(s):  
Surface Plasmon ◽  
Peak Position ◽  
Fused Silica ◽  
Linear Variation ◽  
The Core ◽  
Nanocrystalline Thin Film ◽  
Plasmon Peak ◽  
Superlattice Structures ◽  
Film Form ◽  
Absorbance Spectra

Nanocrystalline Aux Cu1–x films were synthesized by depositing Cu/Au/Cu multilayer in nanocrystalline thin film form with requisite thickness of individual layers onto fused silica substrates by high pressure sputtering technique. The absorbance spectra showed only one surface plasmon peak for all the compositions with the exception that the peak position did not indicate gradual shift as gold concentration was increased. Peak position for the two compositions corresponding to the two superlattice structures, AuCu3 and AuCu, deviated significantly from linear variation. The experimental results have been discussed in light of the existing Mie theory and the Core-shell model.

Investigation of phase separation in InGaN alloys by plasmon loss spectroscopy in a TEM

MRS Advances ◽  
2016 ◽  
Vol 1 (40) ◽  
pp. 2749-2756 ◽  
Author(s):  
Xiaoyi Wang ◽  
Marie-Pierre Chauvat ◽  
Pierre Ruterana ◽  
Thomas Walther
Keyword(s):  
Phase Separation ◽  
Core Loss ◽  
Radiation Sensitivity ◽  
Indium Content ◽  
Peak Position ◽  
Low Loss ◽  
Plasmon Peak ◽  
Core Losses ◽  
Plasmon Loss ◽  
Binary Compounds

ABSTRACTPhase separation of InxGa1-xN alloys into Ga-rich and In-rich regions was observed by a number of research groups for samples grown with high indium content, x. Due to the radiation sensitivity of InGaN to beam damage by fast electrons, high-resolution imaging in transmission electron microscopy (TEM) or core-loss electron energy-loss spectroscopy (EELS) may lead to erroneous results. Low-loss EELS can yield spectra of the plasmon loss regions at much lower electron fluxes. Unfortunately, due to their delayed edge onset, the low energetic core losses of Ga and In partially overlap with the plasmon peaks, all of which shift with indium content.Here we demonstrate a method to quantify phase separation in InGaN thin films from the low-loss region in EELS by simultaneously fitting both plasmon and core losses over the energy range of 13-30eV. Phase separation is shown to lead to a broadening of the plasmon peak and the overlapping core losses, resulting in an unreliable determination of the indium concentration from analyzing the plasmon peak position alone if phase separation is present. For x=0.3 and x=0.59, the relative contributions of the binary compounds are negligibly small and indicate random alloys. For xnom.=0.62 we observed strong broadening, indicating phase separation.

scholarly journals A Portable Setup for Molecular Detection by Transmission LSPR

2012 ◽  
Vol 1479 ◽  
pp. 27-32
Author(s):  
Giulia Cappi ◽  
Enrico Accastelli ◽  
Fabio M. Spiga ◽  
Vera Cantale ◽  
Maria A. Rampi ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Hybridization ◽  
Detection System ◽  
Low Cost ◽  
Peak Position ◽  
Hybridization Experiment ◽  
Localized Surface Plasmon ◽  
Light Sources ◽  
Array Measurements ◽  
Plasmon Peak

ABSTRACTIn the framework of bioanalytics and multiple array detection, we developed a fully portable and low-cost detection system based on Localized Surface Plasmon Resonance (LSPR) in a transmission configuration (T-LSPR). The transmission approach is suitable to be scaled to small dimension systems and to enable high-density array measurements on the same platform. Our setup is made out of off-the-shelf components and consists of a set of discrete light sources and a couple of light-detectors which enable a differential measurement setup. An algorithm fits the measured data and extracts the information of the plasmon peak position in the spectrum.The performance of our T-LSPR measurement system has been characterized on a set of Fluorinated Tin Oxide-coated glass slides covered with gold Nanoislands (NIs). The samples have been modified with a single-stranded DNA layer and a real-time DNA hybridization experiment has been performed. Here we demonstrate that the proposed T-LSPR device, based on the characterization of the plasmon peak with a differential approach, is able to monitor real-time DNA hybridization on surface, and to precisely measure the position of the peak with a standard deviation in wavelength of 0.2 nm.

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

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