Backscattered electron mode

The main drawbacks of this approach are the low availability of such instruments in laboratories, and the fact that many samples are sensitive to ion beam damage, require specific preparation (95), and can induce low contrast. Moreover, the imaging between two milling periods is typically performed in the backscattered electrons mode, which is not always favorable this is the case for carbon nanotubes in a polymer matrix as the atomic number contrast is low. This is probably the reason why, even if the FIB/SEM approach is used on polymer nanocomposites, it not used in the literature for carbon nanotubes in polymer matrix. In this last application, the tomo-STEM technique is a good alternative to obtain images of relatively thick samples with high contrast and resolution (91). 

SEM of constituent particles in AA7075-T651 imaged in backscattered electron mode. (Image courtesy of Nick Birbilis.)... 

Figure 3 The SEM pictures of Pd/C type 2 catalyst a)secondary mode, b) backscattered electron.

Imaging Modes Secondary Electrons (ET) Backscattered Electrons Secondary Electrons (ESD) Backscattered Electrons... 

Scanning electron micrographs (SEM) were obtained using a JSM 5500 LV (Jeol, Japan) electron microscope. The observations were performed in a secondary electron (SE) and in a backscattering electron (BSE) mode at a low vacuum pressure of 12 kPa. 

Electron backscatter diffraction (EBSD) — The focused electron beam of Scanning Electron Microscopes (SEM) can be used to detect the crystallographic orientation of the top layers of a sample. The backscattered electrons (information depth 40-70 nm at 25 kV accelerating potential, lateral resolution around 200 nm) provide characteristic diffraction patterns (Kikuchi lines) on a phosphor screen. The patterns are recorded by a CCD-camera and interpreted by software. The position of the unit cell of the sample is determined by the corresponding Euler angles. In scanning mode, the software produces a surface orientation mapping that consists of... 

Microscopic measurements were performed by using a Quanta 200 ESEM (environmental scanning electron microscopy) instrument (EEY Company), operating in low-vacuum mode, with an electron beam emitted at 25 or 30 kV under 1 Torr (133 Pa) pressiue. Solid-state backscatter detector (SSB) allowed collecting backscattered electrons emitted from the samples. 

Figure 1. Backscattered electron (BSE) images of the morphology of powders processed under shearing mode by reactive mechanical alloying under hydrogen, a) 2Mg-Co mixture milled for 30h using WD=10 mm and BPWR=10 1 and b) Mg-2B (crystalline (c) boron) mixture milled for 5h using WD=5 mm and BPWR=44 1. RPM=60 applied during milling.

Figure 7.24 SEM images in backscattered electron (BSE) mode (a) and cathodolumines cence (CL) mode (b) of an APS hydroxyapatite coating immersed for 7 days in simulated body fluid (EHBSS) (Gotze, Hildebrandt...

Count rates in EDX are generally much lower than in backscattering or secondary electron mode and so it is often used for quantitative analysis of particular points of interest within a backscattered or secondary electron image, although EDX images can also be acquired if necessary. The same is true of SAM. 

Basic Principles. In a HREELS experiment, a monokinetic electron beam with a primary energy, Ep, interacts with the surface region in different ways exciting vibrational modes [47] and electronic states [48]. Intensity of the backscattered electrons is measured versus primary energy for a given direction as shown in Figure 13. 

Experiments. The micro structure of the mortar beams is investigated with a Philips XL 30 FEG Scanning Electron Microscope (SEM). For the analysis in the secondary electrons (SE) mode, freshly broken surfaces are prepared. Polished surfaces are analyzed in the backscattered electrons (BSE) mode. The final polishing stage is carried out with a 1 pm diamond paste. In order to render the mortar surface conductive, samples are coated by evaporation with gold prior to the SEM investigation. 

Eor surface imaging the most common operation modes use signals of backscattered electrons and secondary electrons (Egerton 2005). While the electron beam scans the surface... 

Figure 7.28. The image illustrates two different scanning modes of a scanning electron microscope (SEM). In the lower part of the image, we can see the relief of the sample. This is obtained nsing the detection of secondary electrons. In the upper part of the image, we can see light spots surrounded by darker areas. The light spots correspond to the zirconium aggregates in an aluminium matrix. This is obtained using the detection of backscattered electrons.

The microstructure of the as received samples was observed by scanning electron microscopy (SEM) using both secondary electron and backscattered electrons image modes. Selected aged samples were also polished for SEM observations. 

---