Energy disperse X-ray detection

Bowen JH, Woodward BH, Mossier JA, et al. 1980. Energy dispersive x-ray detection of thorium dioxide. Arch Pathol Lab Med 104 459-461. 

Among the variety of micro-analytical techniques used, electron probe X-ray micro-analysis (EPXMA) and computer controlled scanning electron microscopy with energy-dispersive X-ray detection (CC-SEM/EDX) are most commonly used. Both can be used in fully automated mode, and in combination with cluster analysis and/or multivariate techniques. They are ideally suited for the analysis of representative numbers (300-1000... 

Field Emission Gun with Energy Dispersive X-ray detection (FEG/EDX) interfaced with MRS is illustrated in Fig. 8, where it is observed that the particle has undergone changes after exposure to the electron beam. In addition, Raman spectra obtained after exposure to the electron beam showed band broadening, higher background and lower spectral quality. To this end, the importance of a robust protocol to be used for the analysis of environmental particles (especially of the finer fraction) with an interfaced two tier approach has been illustrated. It also seems from these preliminary observations that the protocol may have to be particle type specific. In addition, particle behaviour when exposed to the interfaced instrument may not mirror its behaviour when analysed under stand-alone conditions. 

Chong et al. [742] have described a multielement analysis of multicomponent metallic electrode deposits, based on scanning electron microscopy with energy dispersive X-ray fluorescence detection, followed by dissolution and ICP-MS detection. Application of the method is described for determination of trace elements in seawater, including the above elements. These elements are simultaneously electrodeposited onto a niobium-wire working electrode at -1.40 V relative to an Ag/AgCl reference electrode, and subjected to energy dispersive X-ray fluorescence spectroscopy analysis. Internal standardisation... 

In HRTEM, very thin samples can be treated as weak-phase objects (WPOs) whereby the image intensity can be correlated with the projected electrostatic potential of crystals, leading to atomic structural information. Furthermore, the detection of electron-stimulated XRE in the electron microscope (energy dispersive X-ray spectroscopy, or EDX, discussed in the following sections) permits simultaneous determination of chemical compositions of catalysts to the sub-nanometer level. Both the surface and bulk structures of catalysts can be investigated. 

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