Scanning electron microscopy secondary electrons

Scanning Electron Microscopy Scanning Electron Microprobe Secondary Electron Miscroscopy Secondary Electron Backscatteted Electron... 

Surface analytical methods — Important ex situ methods for surface analysis are X-Ray Photoelectron Spectroscopy (XPS) UV-Photoelectron Spectroscopy (UPS), Auger Electron Spectroscopy (AES), Ion Scattering Spectroscopy (ISS), Rutherford Backscattering (RBS), Secondary Ion Mass Spectroscopy (SIMS), Scanning Electron Microscopy (SEM), Electron Microprobe Analysis (EMA), Low Energy Electron Diffraction (LEED), and High Energy Electron Diffraction (RHEED). 

Rutherford backscattering spectroscopy Scanning electron microscopy Secondary ion mass spectroscopy Single crystal X-ray diffraction Small angle X-ray and neutron scattering Spark source mass spectrometry Transmission electron microscopy Voltametry... 

This chapter describes the results of an ongoing study we are conducting into the nanoscale mechanical properties, chemical composition and structure of healthy enamel, carious lesions and the acquired salivary pellicle layer. A variety of material characterization techniques are being used, including nanoindentation, scanning electron microscopy (SEM), electron microprobe analysis (EMPA), scanning acoustic microscopy, atomic force microscopy (AFM) and time-of-flight secondary ion mass spectroscopy (TOF SIMS). 

SEM (scanning electron microscopy)—an electron beam is focused onto a small region of a sample contained within a vacuum. The beam is scanned across the sample and the backscattered electrons (those undergoing elastic collisions) and the secondary electrons (those electrons released through inelastic collisions) are collected on a positively charged detector to obtain an image on a scintillation screen or electronic detector. 

The interface properties can usually be independently measured by a number of spectroscopic and surface analysis techniques such as secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy (XPS), specular neutron reflection (SNR), forward recoil spectroscopy (FRES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), infrared (IR) and several other methods. Theoretical and computer simulation methods can also be used to evaluate H t). Thus, we assume for each interface that we have the ability to measure H t) at different times and that the function is well defined in terms of microscopic properties. 

Further structural information is available from physical methods of surface analysis such as scanning electron microscopy (SEM), X-ray photoelectron or Auger electron spectroscopy (XPS), or secondary-ion mass spectrometry (SIMS), and transmission or reflectance IR and UV/VIS spectroscopy. The application of both electroanalytical and surface spectroscopic methods has been thoroughly reviewed and appropriate methods are given in most of the references of this chapter. 

Scanning electron microscopy (SEM) seems to have been used only scarcely for the characterization of solid lipid-based nanoparticles [104], This method, however, is routinely applied for the morphological investigation of solid hpid microparticles (e.g., to smdy their shape and surface structure also with respect to alterations in contact with release media) [24,38,39,41,42,80,105]. For investigation, the microparticles are usually dried, and their surface has to be coated with a conductive layer, commonly by sputtering with gold. Unlike TEM, in SEM the specimen is scanned point by point with the electron beam, and secondary electrons that are emitted by the sample surface on irradiation with the electron beam are detected. In this way, a three-dimensional impression of the structures in the sample, or of their surface, respectively, is obtained. 

Although a number of secondary minerals have been predicted to form in weathered CCB materials, few have been positively identified by physical characterization methods. Secondary phases in CCB materials may be difficult or impossible to characterize due to their low abundance and small particle size. Conventional mineral identification methods such as X-ray diffraction (XRD) analysis fail to identify secondary phases that are less than 1-5% by weight of the CCB or are X-ray amorphous. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM), coupled with energy dispersive spectroscopy (EDS), can often identify phases not seen by XRD. Additional analytical methods used to characterize trace secondary phases include infrared (IR) spectroscopy, electron microprobe (EMP) analysis, differential thermal analysis (DTA), and various synchrotron radiation techniques (e.g., micro-XRD, X-ray absorption near-eidge spectroscopy [XANES], X-ray absorption fine-structure [XAFSJ). 

In scanning electron microscopy (SEM), a finely focussed electron beam probe moves from one point on the specimen to the next to form a raster pattern, just as in television imaging. The intensity of scattered or secondary electrons is continuously... 

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