Interface metal-dielectric

Electromagnetic field of a surface plasmon is confined at the metal-dielectric interface and decreases exponentially into both media, Figure 6. 

R8. Rose, G. S., and Ward, S. G., Contact electrification across metal-dielectric and dielectric-dielectric interfaces, Brit. J. Appl. Phys. 8, 121 (1957). 

Thin films of an amorphous-composite In/InO, which contain a metal-dielectric interface, have been studied (12)(13) and found to superconduct when the electron carrier density reaches a value of approximately 1020cm-3. This system, having a Tc of 2.5 to 3.2 K, has been described as exhibiting "interface-dominated superconductivity". 

Solving Maxwell s equations at the metal/dielectric interface at the appropriate boundary conditions yields the surface plasmon dispersion relation, that is, the relation of the angular frequency co and the x-component of the surface plasmon wave vector kSP,... 

Fig. 3. Schematic drawing of a fluorophore positioned close to a metal/dielectric interface. Different fluorescence decay channels operate at different fluorophore/ metal separation distances.

Surface plasmons, or surface plasmon polaritons, are surface electromagnetic waves that propagate inside a metal along a metal/dielectric (or metal/ vacuum) interface their excitation by light is surface plasmon resonance (SPR) for planar surfaces or localized surface plasmon resonance (LSPR) for nanometer-sized metal particles. 

Surface plasmons (SPs) are surface electromagnetic waves that propagate parallel along a metal/dielectric interface. For this phenomenon to occur, the real part of the dielectric constant of the metal must be negative, and its magnitude must be greater than that of the dielectric. Thus, only certain metals such as gold, silver, and aluminum are usually used for SPR measurements. The dispersion relation for surface plasmons on a metal surface is ... 

The approaches to metal enhanced fluorescence proposed in literature are manifold. Depending on the strategy adopted for the fabrication of metallic-dielectric interfaces where plasmons can be localized, it is possible to divide such approaches in two main categories surface roughness-based and nanoclusters-based techniques. 

FT-RAIRS measurements of CO have also been used to identity facets of oxide supported Cu particles [78, 82]. The low sensitivity of RAIRS on single crystal ZnO(OOOl) prevented the observation of adsorbed CO or CO2, despite their observation in NEXAFS [78], although the local metallic dielectric allowed CO to be observed on the Cu particles. There appear to be no examples of HREELS being used to carry out vibrational spectroscopy of adsorbates on oxide supported metal particles. A HREELS study of Ag on MgO(lOO) films [95] was used only to characterise the Ag induced attenuation in the substrate Fuchs-Kliewer phonons, and the appearance of the metal/oxide interfacial plasmon at higher energies. HREELS has also been used to characterise the oxide/oxide interface between NiO and thin film MgO(lOO) [96]. Similar measurements of substrate phonon attenuation were made in HREELS studies on Pt films grown on ZnO(OOOl) [97]. 

Surface plasmon resonance (SPR) biosensors exploit special electromagnetic waves-surface plasmon-polaritons-to probe interactions between an analyte in solution and a biomolecular recognition element immobilized on the SPR sensor surface. A surface plasmon wave can be described as a light-induced collective oscillation in electron density at the interface between a metal and a dielectric. At SPR, most incident photons are either absorbed or scattered at the metal/dielectric interface and, consequently, reflected light is greatly attenuated. The resonance wavelength and angle of incidence depend upon the permittivity of the metal and dielectric. 

The SPR can be simply formalized, in a first approach, by solving Laplace s equation in tlie case of a single conducting sphere surrounded by a homogeneous transparent medium, with tlie appropriate continuity relations at the metal-dielectric interface and assuming tliat the sphere radius is much lower than the wavelength (quasistatic approximation). The homogeneous local electric field inside the particle, E, then writes... 

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