Nonlinear inelastic electron scattering revealed by plasmon-enhanced electron energy-loss spectroscopy

This work presents the application of the technique known as high resolution electron energy loss spectroscopy (HREELS) to the study of a modern technological surface. First the physics of the interaction of low energy electrons with surfaces is briefly reviewed. The dielectric theory of inelastic electron scattering is outlined, with its application to surfaces and the excitation of phonons, polaritons and plasmons. Then a study of the modification of a graphite surface by Ar and H ion bombardment is presented, in relation with graphite surfaces modified by plasma wall interactions in fusion reactors. The observations of phonons and low energy plasmons are reported, with the C–H stretching vibrations as well following the H + bombardment. These observations are related to structural and chemical modifications induced by the ion bombardment.

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SURFACE STUDIES BY CORE-EXCITATION REFLECTION ELECTRON ENERGY LOSS SPECTROSCOPY

Surface Review and Letters ◽

10.1142/s0218625x95000054 ◽

1995 ◽

Vol 02 (01) ◽

pp. 43-61 ◽

Cited By ~ 5

Author(s):

A.P. HITCHCOCK ◽

T. TYLISZCZAK

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Inelastic Electron ◽

Core Excitation ◽

X Ray ◽

Molecular Adsorbates ◽

Momentum Transfer Dependence ◽

Electron Energy Loss ◽

X Ray Absorption

Inelastic electron scattering in a reflection geometry is a useful alternative to synchrotron radiation X-ray absorption spectroscopy for inner-shell excitation studies of surfaces. This article reviews the current capabilities of reflection electron energy loss spectroscopy for core-excitation studies of the electronic and geometric structure of surfaces. Issues discussed include: momentum transfer dependence, comparison to X-ray techniques, orientational sensitivity, spatial and energy resolution, and technological applications. Examples of applications to clean surfaces, atomic and molecular adsorbates, and thin films are given.

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Data Acquisition and Handling Unit for a Quantitative Use of Electron Energy Loss Spectroscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078699 ◽

1977 ◽

Vol 35 ◽

pp. 232-233 ◽

Cited By ~ 1

Author(s):

P. Trebbia ◽

P. Ballongue ◽

C. Colliex

Keyword(s):

Electron Microscope ◽

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Single Channel ◽

Detection System ◽

Surface Barrier ◽

Solid State Detector ◽

Electrostatic Mirror ◽

Electron Energy Loss

An effective use of electron energy loss spectroscopy for chemical characterization of selected areas in the electron microscope can only be achieved with the development of quantitative measurements capabilities.The experimental assembly, which is sketched in Fig.l, has therefore been carried out. It comprises four main elements.The analytical transmission electron microscope is a conventional microscope fitted with a Castaing and Henry dispersive unit (magnetic prism and electrostatic mirror). Recent modifications include the improvement of the vacuum in the specimen chamber (below 10-6 torr) and the adaptation of a new electrostatic mirror.The detection system, similar to the one described by Hermann et al (1), is located in a separate chamber below the fluorescent screen which visualizes the energy loss spectrum. Variable apertures select the electrons, which have lost an energy AE within an energy window smaller than 1 eV, in front of a surface barrier solid state detector RTC BPY 52 100 S.Q. The saw tooth signal delivered by a charge sensitive preamplifier (decay time of 5.10-5 S) is amplified, shaped into a gaussian profile through an active filter and counted by a single channel analyser.

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Trends in Electron Energy Loss Spectroscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078675 ◽

1977 ◽

Vol 35 ◽

pp. 228-229

Author(s):

C. Colliex ◽

P. Trebbia

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Materials Science ◽

Analytical Technique ◽

Recent Developments ◽

Quantitative Results ◽

Electron Microscopes ◽

Electron Energy Loss ◽

Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

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Signal/Noise Ratio and Elemental Detectivity by Eels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054893 ◽

1982 ◽

Vol 40 ◽

pp. 488-489

Author(s):

R. F. Egerton

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Elemental Analysis ◽

Electron Energy Loss Spectroscopy ◽

Emission Spectroscopy ◽

X Ray ◽

Signal Noise ◽

Characteristic Signal ◽

Noise Ratio ◽

Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

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