Scanning electron microscopy back-scattered electrons

Fig. 30 SEM/BSE (Scanning Electron Microscopy/Back Scattering Mode) images of microdeformation of both a non-nucleated and b -modified PP/EPR grades described in Sect. 5.4 tested at 1 m s 1 and room temperature...

Abstract Surface analyses have been one of the key technologies for corrosion control and surface finishing. It is very important that the most appropriate apparatus for the purpose of the analyses should be selected from various analytical techniques. In this chapter, surface analytical methods for corrosion control and surface finishing, such as X-ray fluorescence analysis (XRF), X-ray diffraction analysis (XRD), X-ray photo-electron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES), Secondary ion mass spectrometry (SIMS), Rutherford back-scattering spectrometry (RBS), Surface-enhanced Raman spectroscopy (SERS), Fourier-transform infrared spectroscopy (FTIR), and so on, are briefly introduced. 

FIGURE 3.6. Scanning electron microscopy in back-scatter mode of a 400 nm by 1.5 /xm striped Au/Ni/Au/Ni/Pt nanorod at 35,000x. (Reproduced with permission from Angew. Chem. Int. Ed 2005, 44, 744-6. Copyright 2005 Wiley Inter Science.)... 

Scanning Electron Microscopy (SEM) [21], Topographical images in a SEM are formed from back-scattered primary or low-energy secondary electrons. The best resolution is about 2-5 nm but many routine studies are satisfied with a lower value and exploit the... 

Figure 8.5 Varnish micromorphology form ranges from botryoidal to lamellate (A and C). Two types of imagery show botryoidal varnishes from Kitt Peak, Arizona (A) the topography by secondary electrons (B) the same structures from the bottom upwards with back-scattered electrons - showing the layering structures inside each nudeation centre. (C and D) Scanning electron microscopy images of lamellate clay minerals accreting on rock varnish in Death Valley, California. (C) Individual clay platelets overlap as they cement onto the surface. (D) The clays impose a lamellate structure in cross-section, as first noticed by Potter and Rossman (1977).

Fig. 1. Experimental techniques available for surface studies. SEM = Scanning electron microscopy (all modes) AES = Auger electron spectroscopy LEED = low energy electron diffraction RHEED = reflection high energy electron diffraction ESD = electron stimulated desorption X(U)PS = X-ray (UV) photoelectron spectroscopy ELS = electron loss spectroscopy RBS = Rutherford back scattering LEIS = low energy ion scattering SIMS = secondary ion mass spectrometry INS = ion neutralization spectroscopy.

Field emission scanning electron microscopy (FESEM), glancing incidence x-ray diffraction (GIXRD), transmission electron microscopy (TEM), micro Raman scattering, Fourier transform inftaied (FTIR) spectrometry, Rutherford back scattering (RBS) studies and electron probe micro analysis (EPMA) have been carried out to obtain micro-structural and compositional properties of the diamond/p-SiC nanocomposite films. Atomic force microscopy (AFM) and indentation studies have been carried out to obtain film properties on the tribological and mechanical front. 

In scanning electron microscopy, electrons emitted by an electron gun (primary electrons) are focused by means of Wehnelt cylinders and electromagnetic lenses onto the sample surface, which they scan line by line (Fig. 2). The secondary and back-scattered electrons emitted by the sample are captured by detectors and presented in the form of brightness modulation on, eg, a monitor. The secondary electrons come from a surface layer up to 10 nm thick, while the back-scattered electrons usually originate from deeper layers. 

Figure 13. Scanning Electron Microscopy image (Back scattered electrons mode) of a zirconia toughened alumina nano composite, showing the narrow distribution of well dispersed zirconia particles in an alumina matrix [39],...

Scanning electron microscopy micrographs taken in the normal mode do not always permit effective observation of features on fiber surfaces. Display modes such as deflection or Y modulation and imaging modes such as back-scattered electron imaging (BEI) can provide clearer contrast, as shown in Figs 5.5 and 5.6. Heat aging of polymer fibers can cause cyclic trimers and oligomers to diffuse to the fiber... 

ESEM (Environmental Scanning Electron Microscopy) with an EDX (Energy Dispersive X-ray) attachment was used to provide surface chemistry data. The ESEM is equipped with a LaBa gun and is fully equiped with a range of secondary electron and back scattered electron detectors. Corrections for atomic number, absorbtion and fluorescence are achieved through a virtual standard calibration routine. The EDX... 

The dangling bonds of a Si surface abstract one F atom from an incident F2 molecule while the complementary F atom is scattered back into the gas phase [20]. This abstractive mechanism leads to F adsorjDtion at single sites rather than at adjacent pairs of sites, as observed directly by scanning tunnelling microscopy [21]. Br atoms adsorb only to Ga atoms in the second layer of GaAs(001)-(2 x 4) where empty dangling bonds on the Ga atoms can be filled by electrons from the Br atoms [22]. 

Electron Beam Techniques. One of the most powerful tools in VLSI technology is the scanning electron microscope (sem) (see Microscopy). A sem is typically used in three modes secondary electron detection, back-scattered electron detection, and x-ray fluorescence (xrf). AH three techniques can be used for nondestmctive analysis of a VLSI wafer, where the sample does not have to be destroyed for sample preparation or by analysis, if the sem is equipped to accept large wafer-sized samples and the electron beam is used at low (ca 1 keV) energy to preserve the functional integrity of the circuitry. Samples that do not diffuse the charge produced by the electron beam, such as insulators, require special sample preparation. 

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