Low-energy electron microscope

The past decade saw introduction of the low-energy electron microscope (LEEM) (12). It was expected potentially to be capable of moderately high resolution (6-mn) video-rate imaging of surfaces and interfaces. This would make it capable of studying dynamic processes at surfaces, thin-fibn growth, strain relief, etching, absorption. 

Frank L, Mullerova I, Faulian Kand Bauer E 1999 The scanning low-energy electron microscope first attainment of diffraction contrast in the scanning electron microscope Scanning 21 1-13... 

The good agreement between electrochemical and UHV data, documented in Figure 4, is a very important result, because it proves for the first time that the microscopic information which one obtains with surface science techniques in the simulation studies is indeed very relevant to interfacial electrochemistry. As an example of such microscopic information, Figure 5 shows a structural model of the inner layer for bromide specific adsorption at a halide coverage of 0.25 on Ag 110 which has been deduced from thermal desorption and low energy electron diffraction measurements /12/. Qualitatively similar models have been obtained for H2O / Br / Cu( 110) /18/and also for H2O/CI /Ag 110. ... 

In this section we apply the theory developed in the preceding sections to a series of experiments carried out by Schmitt et al using the so-called reaction microscope for ultra-low energy electrons emitted from neutral target atoms. This state of the art experimental technique has enabled experimentalists to measure simultaneously the momenta of the emitted electrons and the recoiling residual-target ion and many new striking features have been found. 

Some of the techniques described in this chapter used most widely today are Auger electron spectroscopy, X-ray photoelectron spectroscopy, electron-probe micro-analysis, low energy electron diffraction, scanning electron microscope, ion scattering spectroscopy, and secondary ion mass spectroscopy. The solid surface, after liberation of electrons, can be analyzed directly by AES, XPS, ISS, and EPMA (nondestructive techniques), or by liberation of ions from surfaces using SIMS (involving the destruction of the surface). Apart from the surface techniques, reflectance-absorbance infrared (RAIR) spectroscopy has also been employed for film characterization (Lindsay et al., 1993 Yin et al., 1993). Some... 

Several other techniques referred to as microscopy and based on several different phenomena can be found in the literature. These include acoustic microscopy based on the interactions of acoustic waves with materials [28] the projection microscopy which is still under development and gives a hologram image of the sample illuminated by a beam of low energy electrons [29]. For membrane applications a scarming electrochemical microscope has been developed based on the measurement of the local flux of electroactive ions across the membrane. The ability to detect 1 pm radius pores separated by 50-100 pm has been demonstrated with mica membranes [30]. 

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