Energy-dispersive X-ray Spectroscopy EDXS

Physically the generation of X-rays is often a secondary process preceded hy the ionization of an atom. There are, therefore, several possihilities of X-ray generation depending on the type of the exciting medium - neutrals or charged particles such as electrons and ions and high-energy photons, i. e. X-rays themselves. 

In these approximations for the K series the value 1 is subtracted from the atomic number Z to correct for the screening of the nuclei by the remaining K-shell electron. For the L series the screening effect of the two K-shell electrons and the seven remaining L-shell electrons must be taken into consideration by subtracting 7.4. 

The energy E of the characteristic X-rays within a given series of lines, i.e. Ka, K/J, etc., increases regularly with the atomic number Z. This dependence is called Moseley s law of X-ray emission  

In an electron-excited X-ray spectrum the discrete X-ray lines are superimposed on a continuous background this is the well-known bremsstrahlung continuum ranging from 0 to the primary energy Eq of the electrons. The reason for this continuum is that because of the fundamental laws of electrodynamics, electrons emit X-rays when they are decelerated in the Coulomb field of an atom. As a result the upper energy limit of X-ray quanta is identical with the primary electron energy. 

The phenomena of beam broadening as a function of specimen thickness are illustrated in Fig. 4.20 each figure represents 200 electron trajectories in silicon calculated by Monte Carlo simulations [4.91, 4.95-4.97] for 100-keV primary energy, where an infinitesimally small electron probe is assumed to enter the surface. In massive Si the electrons suffer a large number of elastic and inelastic interactions during their paths through the material, until they are finally completely stopped. The resulting penetration depth of the electrons is approximately 50 pm and in the 

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The introduction of sulphonic acid groups (-S03H) onto the PE surface was substantiated by FTIR, energy-dispersive X-ray spectroscopy (EDX) and XPS techniques. The appearance of signal at 1038 cm 1 and band at 1156 cm 1 in the FTIR spectrum of photo-modified PE film is attributed to... 

Current methods used to image MCM-41 include (1) analytical transmission electron microscopy (TEM) to determine structure, size, morphology, and local chemical composition (2) energy-dispersive X-ray spectroscopy (EDXS) in a scanning electron microscope (SEM) to determine chemical composition 5 and (3) electron energy loss spectroscopy (EELS) for elemental analysis.6... 

Energy Dispersive X-ray Spectroscopy (EDX)/ Transmission Electron Microscopy (TEM) High resolution identification of the chemical composition and secondary structures formed... 

Selected samples from various experiments were analyzed in energy dispersive X-ray spectroscopy (EDX). These analyses were carried out on a Hitachi S-4500 field emission scanning electron microscopy equipped with an EDAX Phoenix model EDX spectrometer. An electron beam of 15 kV was used. These samples were also analyzed in a Krafos Axis Ulfra X-ray phofoelectron spectroscopy (XPS). 

Fig. 11 Top weight changes of AZ91D alloy samples vs immersion time in Bmim-NTfr Bottom chemical composition of the sample surface determined via energy dispersive X-ray spectroscopy (EDXS) showing the buildup of a contamination layer. Image adapted from [217]. Image Copyright Wiley-VCH (2007)...

Microscope (SEM) and Atomic Force Microscope (AFM). The variation of the crystallinity was analyzed using X-Ray Diffraction Spectroscopy (XRD). The element concentration of the annealed electroless plated films was investigated using Energy Dispersive X-Ray Spectroscopy (EDX). 

BET surface areas of the porous films were measured by nitrogen adsorption at -196 °C after the BET method by using a Fisons Sorptomatic 1900. The surface of the catalysts and the pore structure were examined by scanning electron microscopy (SEM) in a Hitachi S-570 scanning electron microscope. The concentration profile of the chemical elements along the oxide film was determined by energy-dispersive X-ray spectroscopy (EDX). 

Energy dispersive x-ray spectroscopy (EDXS or EDS) A method for elemental analysis based on using a focussed electron beam (in an electron microscope) to cause the fluorescence of secondary x-rays from atoms in a specimen. 

Figure 3.7 shows the perforated and pitted areas of the boiler tubes, respectively. The region near the pit, which is thinned due to corrosion, had shown the layers of deposits over the surface. The deposits, when analyzed by energy-dispersive X-ray spectroscopy (EDX), showed the presence of V, S, Al, Si, and O (Figure 3.8). Electron probe microanalysis (EPMA) showed that the deposits were rich in V compounds near the pit (Figure 3.9). Although floor-area tube temperature is normally between 300°C and 450°C, the deposit would increase the temperature due to poor heat transfer effect, which is sufficient to cause melting of the salt compounds in the deposit. Once these salts are in molten state, they would undergo fluxing reaction, destroying the protective layer, and consequently, the metal undergoes hot corrosion. The presence of V and S as noticed on pits...

As far as bioindicator plants are subject to change at chemical and anatomic levels due to the action of anthropogenic enviromnent pollution, these transformations may be effectively monitored with the aid of FTIR speetroseopy, SEM, and energy-dispersive X-ray spectroscopy (EDX) [8,9]. 

Nanoaerosol can be sampled on a filter or grid for offline analyses of the morphology and composition of individual particles. The most common offline method is transmission electron microscope (TEM) and energy-dispersive X-ray spectroscopy (EDX). However, the physical and chemical properties may change due to agglomeration and/or chemical reactions during the sampling, transport, and offline characterization processes. 

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