Showing papers on "Plasmon published in 1970"
TL;DR: In this paper, the effects of the spatial variation of the electron density on the surface-plasmon dispersion relation were investigated, and it was shown that measurements of that relation are a useful probe of electron density in the surface region.
Abstract: The effects of the spatial variation of the electron density on the surface-plasmon dispersion relation are investigated. We show that measurements of that relation are a useful probe of the electron density in the surface region. Previous calculations on homogeneous materials have predicted a linear or quadratic dependence of the frequency on momentum parallel to the surface. We find that the usual surface-plasmon resonance frequency at first decreases with increasing momentum and then increases with further increases in momentum. This behavior agrees with the experimentally observed dispersion. Additional higher-frequency surface modes, similar to those observed in laboratory plasmas, are identified.
183 citations
159 citations
TL;DR: In this article, the authors describe measurements of the reflectivity, scattering, and transmission of light by metals with rough surfaces, and compare the experimental results with the scalar scattering theory and make some general comments about the properties of surface dipoles and currents.
Abstract: This paper describes measurements of the reflectivity, scattering, and transmission of light by metals with rough surfaces. For surfaces whose roughness is very short ranged, the ratio of rough-surface reflectivity to smooth-surface reflectivity varies exponentially as ${\ensuremath{\lambda}}^{\ensuremath{-}2}$ both above the plasmon frequency and in regions where ${\ensuremath{\epsilon}}_{2}\ensuremath{\gg}|{\ensuremath{\epsilon}}_{1}|$. In the latter regions for these rough surfaces, the scattered intensity follows a ${\ensuremath{\lambda}}^{\ensuremath{-}4}$ wavelength variation. For surfaces which are more wavy, the reflectivity and scattered light vary less rapidly with wavelength. Well below the plasmon frequency, additional fields not present on smooth surfaces, but coming from induced extra currents and dipoles on rough surfaces, add coherently to the specular beam, with a resonant wavelength variation. Near the plasmon frequency there is extra absorption. We have studied the angular variation of the scattered light, and have observed additional incoherent light associated with these extra dipoles and currents. We compare the experimental results with the scalar scattering theory and make some general comments about the properties of surface dipoles and currents.
95 citations
TL;DR: In this paper, the decay of surface plasmons into one-electron excitations has been obtained in photoemission measurements from a slightly roughened surface of aluminum, and a simple theory has been developed which explains the resultant photoyield in terms of both the drop in reflectance resulting from roughness-aided plasmon coupling, and the relative penetration depth of the fields associated with these excited plasms.
Abstract: Evidence for the decay of surface plasmons into one-electron excitations has been obtained in photoemission measurements from a slightly roughened surface of aluminum. A simple theory has been developed which explains the resultant photoyield in terms of both the drop in reflectance resulting from roughness-aided plasmon coupling, and the relative penetration depth of the fields associated with these excited plasmons.
86 citations
TL;DR: In this article, the mean free path for elastic scattering and for plasmon production was determined from beam attenuation measurements on films of various thicknesses, and the authors showed that elastic scattering can be achieved using a beam attenuator.
Abstract: : The mean free path for elastic scattering and for plasmon production was determined from beam attenuation measurements on films of various thicknesses. (Author)
54 citations
TL;DR: In this paper, p-polarized light incident non-normally on thin Ag films has been observed above the bulk plasma frequency, which is interpreted as being due to excitation of longitudinal plasmons in accordance with recent theoretical predictions.
53 citations
TL;DR: In this paper, the surface plasmons are excited in this experiment by light, and a relatively accurate determination of the optical constants is possible by using gold and silver foils of different thicknesses.
Abstract: Non radiative surface plasmons decay into photons on a rough surface. This light emission is studied with gold- and silver foils of different thicknesses. The surface plasmons are excited in this experiment by light. By this way a relatively accurate determination of the optical constants is possible.
40 citations
TL;DR: Inelastic scattering of electrons by surface plasma oscillation for low energy electron diffraction and photoemission, interpreting surface plasmon excitation as discussed by the authors was used for low-energy electron imaging.
Abstract: Inelastic scattering of electrons by surface plasma oscillation for low energy electron diffraction and photoemission, interpreting surface plasmon excitation
26 citations
25 citations
TL;DR: In this article, a microscopic theory of barrier heights at metal-semiconductor interfaces is proposed, which explains the resonance in barrier adjustability as a function of semiconductor ionicity described by Mead et al.
Abstract: A microscopic theory of barrier heights at metal-semiconductor interfaces is proposed. The theory explains the resonance in barrier adjustability as a function of semiconductor ionicity described by Mead et al., in terms of the interfacial-surface plasmon energy and the covalent-bond energy of the semiconductor.
24 citations
TL;DR: In this article, the excitation of plasma oscillation by X-rays was confirmed by examining the inelastic scattering for chromium Kβ 1 and copper K β 1 rays at various observation angles.
Abstract: Using a crystalline beryllium specimen, the excitation of plasma oscillation by X-rays was confirmed by examining the inelastic scattering for chromium K β 1 and copper K β 1 rays at various observation angles. The X-rays suffered an energy loss, which was equal to the plasmon energy of the solid and also satisfied the dispersion relation predicted by the free electron gas theory. The inelastic scattering was still observed beyond the critical angle estimated by the theory. At lower scattering angles the spectral breadth of the scattering was about 4 eV, which corresponds to the plasmon life time of 1.5×10 -16 sec. As the angle was increased the breadth rapidly broadened and the scattering gradually disappeared.
TL;DR: Plasmon decay by neutrinos emission in strong magnetic field, examining parallel and perpendicular propagation is discussed in this article, where the authors also examine the effects of the magnetic field on the neutrino emission.
Abstract: Plasmon decay by neutrinos emission in strong magnetic field, examining parallel and perpendicular propagation
TL;DR: In this article, the infrared spectral emittance of three samples of tellurium-doped n -type GaSb has been measured at 77°K. To interpret the data, the presence of an electronically depleted surface layer has been assumed.
TL;DR: In this article, the difference between long wave bremsstrahlung and radiative surface plasmon decay (Ag targets) was possible due to different dependecies of the radiation intensity I on electron energy E. The observed I(E)-dependence may be explained if only small wave vector surface plasmons are allowed to radiate.
TL;DR: The surface plasmon radiation was found to be very sensitive to contamination of the film surface by an oxide layer, and the surface resonance was at 10.2 eV and the volume resonance at 15 eV as discussed by the authors.
Abstract: Plasma radiation from thin films of aluminum bombarded by non-normally incident 80 keV electrons has been investigated. Radiative decay of both volume plasmons and surface plasmons was observed with the surface plasmon radiation being very sensitive to contamination of the film surface by an oxide layer. The surface resonance occurs at 10.2 eV, whereas the volume resonance is at 15 eV. These values are in accord with electron energy-loss experiments.
TL;DR: In this paper, the half width of peaks in the specular electron reflectivity curves from copper and nickel (001) surfaces is reported for the electron energy range 10-200 eV.
TL;DR: In this article, the resonance effects associated with surface plasmon excitation (the excitation of evanescent electro-magnetic surface waves) which occur when light is reflected from metal gratings and rough surfaces are described.
Abstract: Described are the resonance effects associated with surface plasmon excitation (the excitation of evanescent electro-magnetic surface waves) which occur when light is reflected from metal gratings and rough surfaces
TL;DR: In this article, the radiative decay of volume plasmons, created in Mg by 80 keV electrons, has been studied and an intrinsic lifetime of (1.14 ± 0.11) × 10 -15 sec and a plasmon energy of (10.43 ± 1.03) eV for Mg have been determined.
TL;DR: In this paper, a comparison between the competing processes of x-ray scattering and photoelectric absorption is made, with particular attention paid to absorption fine-structure and its relevance to the study of the unoccupied energy levels available to electrons in solids.
Abstract: Summary A comparison is made between the competing processes of x-ray scattering and photoelectric absorption. The latter topic is then developed more fully, particular attention being paid to absorption fine-structure and its relevance to the study of the unoccupied energy levels available to electrons in solids. Electron wave scattering theories of metal fine-structure are outlined, together with the simultaneous plasmon emission concept for transition metals and the bound ejected electron theory for the solid halides of potassium.
TL;DR: In this paper, a new measurement of the plasmon mean free path in aluminium based on a new experimental method is reported, which is the first measurement of this path in aluminum.
TL;DR: In this paper, an exact theory of the interaction of a fast electron with plasmons in thin films is presented, and the general shape of the electron energy loss spectrum is described briefly.
TL;DR: In this paper, the Green function method for matching at a surface is extended to the case of three different media with two separating surfaces at a finite distance, and the use of the new secular equation is illustrated with two simple models (one for electrons and one for plasmons) of a slab of material with two free surfaces.
TL;DR: In this paper, it was pointed out that the recent calculations of the absorbing power due to a photon exciting both a plasmon and a photon in an electron gas are incorrect due to the inconsistent treatment of the electron-electron (or electron-plasmon) interaction.
Abstract: It is pointed out that the recent calculations of the absorbing power due to a photon exciting both a plasmon and a photon in an electron gas are incorrect. The error is shown to result from the inconsistent (current non-conserving) treatment of the electron-electron (or electron-plasmon) interaction. The corresponding correct result should give essentially zero contribution owing to the requirement of the conservation law.
TL;DR: In this paper, the energy of the plasmon modes of a closed-shell molecular system was derived using the displacementssj of Hartree-Fock one-electron functions as generator coordinates.
Abstract: A method of calculation for the energy of the plasmon modes of a closed-shell molecular system is derived. The displacementssj of Hartree-Fock one-electron functions are used as generator coordinates. The theory is applied to atomic helium and hydrogen.