Metal-nanoparticle plasmons

Miller, M. M. and Lazarides, A. A. (2006). Seiisitivity of metal nanoparticle plasmon resonance band position to the dielectric environment as observed in scattering. J. Opt. A Pure Appl. Opt. 8 S239-S249. 

Nitzan and Brus developed an analytical formula for the molecular absorption cross section given the model defined above [14]. Figure 9.2 is taken fi"om Ref. [13] and shows the calculated absorption cross section based on the model associated with the photodissociation of I2. (The I2 formed through the absorption process is very short lived.) Photodissociation predicted to be enhanced as the molecule is placed near a silver metal nanoparticle of radius a - 50 nm near the electronic transition resonance position of cat) 22,200 cm . If e eiai(co) is the dielectric fiinction for the metal, a small metal nanoparticle plasmon in air will have its dipolar surface plasmon resonance at frequency <24 such that [1]... 

Maier SA, Kik PG, Atwater HA, Meltzer S, Harel E, Koel BE, Requicha A AG (2003) Local detection of electromagnetic energy transport below the diffraction limit in metal nanoparticle plasmon waveguides. Nat Mater 2(4) 229-232... 

In the second section of this chapter we want to introduce briefly the physics of metal-nanoparticle plasmons, their damping mechanisms, and give an overview of typical time constants of scattering processes involved in the dissipation of the particle plasmon energy. In the third section a brief listing of theoretical models describing the fluorescence of dipoles in front of metallic nanostructures will be given, as well as basic considerations how to interpret experimental data. In the fourth section we want to exemplarily discuss recently performed experiments, where Lissamine molecules have... 

Klar T ef a/1998 Surface-plasmon resonances in single metallic nanoparticles Phys. Rev. Lett. 80 4249... 

CuNPs) in Fig. 7 shows the monodisperse and uniformly distributed spherical particles of 10+5 nm diameter. The solution containing nanoparticles of silver was found to be transparent and stable for 6 months with no significant change in the surface plasmon and average particle size. However, in the absence of starch, the nanoparticles formed were observed to be immediately aggregated into black precipitate. The hydroxyl groups of the starch polymer act as passivation contacts for the stabilization of the metallic nanoparticles in the aqueous solution. The method can be extended for synthesis of various other metallic and bimetallic particles as well. 

The physical properties of metal nanoparticles are very size-dependent. This is clear for their magnetic properties, for which the shape anisotropy term is very important. This is also true for the optical properties of nanoparticles displaying plasmon bands in the visible range (Cu, Ag, Au) and for 111-V... 

Near-Field Optical Imaging of Localized Plasmon Resonances in Metal Nanoparticles... 

In this chapter, we have provided an overview of near-field imaging and spectroscopy of noble metal nanoparticles and assemblies. We have shown that plasmon-mode wavefunctions and enhanced optical fields of nanoparticle systems can be visualized. The basic knowledge about localized electric fields induced by the plasmons may lead to new innovative research areas beyond the conventional scope of materials. 

Okamoto, H. and Imura, K. (2006) Nearfield imaging of optical field and plasmon wavefimctions in metal nanoparticles. 

Figure 8. Illustration of the interaction visible light and the confined electron gas of a metal nanoparticle, resulting in a plasmon resonance.

Photocatalytic Deposition and Plasmon-Induced Dissolution of Metal Nanoparticles on Ti02... 

The reaction was studied for all coinage metal nanoparticles. In the case of GMEs the rate follows zero-order kinetics with IT for all the coinage metal cases. The observed IT for the Cu catalyzed reaction was maximum but its rate of reduction was found to be minimum. Just the reverse was the case for Au and an intermediate value was obtained for the Ag catalyzed reaction (Figure 7). The adsorption of substrates is driven by chemical interaction between the particle surface and the substrates. Here phe-nolate ions get adsorbed onto the particle surface when present in the aqueous medium. This caused a blue shift of the plasmon band. A strong nucleophile such as NaBH4, because of its diffusive nature and high electron injection capability, transfers electrons to the substrate via metal particles. This helps to overcome the kinetic barrier of the reaction. 

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