Surface plasmon band

The final silver cluster diameter increases, at given initial Ag and PVA concentrations, for example from 15 to 50 nm (n 50 times larger), when the part of reduction is increasingly achieved by the donor SPV, rather than by radiolytic radicals [31]. A red shift correlates with the growth in size in the final optical surface plasmon band. Nonirradiated solutions of EDTA silver complex are stable because EDTA does not reduce the ions directly. However, after the appearance of the 400-nm spectrum of silver... 

Extinction calculations for aluminum spheres and a continuous distribution of ellipsoids (CDE) are compared in Fig. 12.6 the dielectric function was approximated by the Drude formula. The sum rule (12.32) implies that integrated absorption by an aluminum particle in air is nearly independent of its shape a change of shape merely shifts the resonance to another frequency between 0 and 15 eV, the region over which e for aluminum is negative. Thus, a distribution of shapes causes the surface plasmon band to be broadened, the... 

Chitosan-stabilized Au NPs can be selectively synthesized on surfaces like poly (dimethylsiloxane) (PDMS) films using HAuC14 as precursor. The computation of surface plasmon bands (SPBs) based on Mie theory and experimental results indicates that the particles are partially coated by chitosan. The proposed mechanism implies that chitosan acts as a reducing/stabilizing agent. Furthermore, PDMS films patterned with chitosan could induce localized synthesis of gold nanoparticles in regions capped with chitosan only [110]. 

Coinage metal nanoparticles (Au, Ag and Cu) have been particularly popular in nanoparticle research because of their easy synthesis, the high intensity of their surface plasmon band and the ease of functionalising the metal surface with ligands such as thiolates. Gold nanoparticles are prepared... 

UV-visible spectra of nanoparticles arise from two sources. The first, more general source is simple Rayleigh scattering that gives rise to the monotonic increase in absorption as wavelength decreases [33]. Au and Ag nanoparticles have intense surface plasmon bands that are valuable additional spectroscopic tools [33-35]. These bands, which arise from a concerted oscillation of nanoparticle electrons, shift with particle size and composition, and are therefore useful handles for the physical characterization of nanoparticle composition. 

A direct experimental measurement of the surface plasmons bands of the gold nanoclusters was not straightforward, since the metallic patterns were quite small and stuck onto an opaque substrate (SiOz). Therefore, we performed theoretical calculations in order to infer the spectral features of the SPs used in our MEF experiments. The absor[ on spectra of gold triangular prisms and cylinders with thicknesses of 35 nm (according to the dimensions of the fabricated patterns) were calculated by using the Discrete dipole approximation (DDA). Further details on the method are ven in references [52-57]. 

The SERS electromagnetic enhancement originates from the resonance between incident radiation and electronic excitation wave on the metal surface, called surface plasmon band, as explained below. The resonance condition depends on the dielectric constant of the metal s (co) = Sj + i 2, which is a complex function of the frequency co. The enhancement factor can be expressed as ... 

The XPS spectra clearly indicated the presence of SiC, as seen in Figures 11.54 [364]. These data should be compared with those of Figure 10.7 [2]. In their XPS energy loss spectra for C(ls) core level, shown in Figure 11.55 [363], there was a known bulk plasmon band at 34 eV and the surface plasmon band at 24 eV. In addition, a band due to SiC was observed at 20 eV. 

As described in papers using gold nanoshells that have also shown surface plasmon bands in the near-1R region [36, 37], the targeted delivery of nanoparticles allows us to... 

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