Electron energy loss spectrometry: Mean free paths for some characteristic X-ray excitations

1976 ◽  
Vol 33 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R. D. Leapman ◽  
V. E. Cosslett
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
Electron Energy Loss

The Application of Electron Energy Loss Spectroscopy in Glass - Ceramic Microstructural Analysis

1977 ◽  
Vol 35 ◽  
pp. 250-251
Author(s):  
R. M. Anderson ◽  
A. Kumar
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Microstructural Analysis ◽  
Elemental Content ◽  
Light Elements ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
C And N ◽  
Electron Energy Loss

The identification of unknown phases in crystallized glasses or ceramics has been difficult because the phases are generally composed of many elements; they crystallize into low-symmetry lattices; they contain numerous impurities, which may alter crystal structure or allow the observation of metastable phases; and they are not well represented in standard compilations of crystal data. Compounding the problem is the fact that energy- dispersive x-ray analysis (EDX) for elemental content can not be employed for elements with Z<11. This eliminates any possibility of qualitative analysis of the important Li, Be, and B glasses as well as determination of O, C and N content. Electron Energy Loss Spectrometry (ELS) has been shown to be a powerful method for the analysis of light elements. The ELS method is far more efficient at detecting light elements than x-ray detection, because the yield of energy loss electrons to inner shell excitation and ionizations is unity and because the electrons, which have lost energy encountering the sample, are scattered through very small angles, with the result that collection efficiencies are high.

Detection limits for Analytical Electron Microscopy with Electron Energy Loss Spectrometry and energy-dispersive x-ray spectrometry

1993 ◽  
Vol 51 ◽  
pp. 594-595
Author(s):  
Dale E. Newbury ◽  
Richard D. Leapman
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Cross Section ◽  
Analytical Electron Microscopy ◽  
Energy Dispersive ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
Analytical Electron ◽  
Electron Energy Loss

The measurement of trace level constituents, arbitrarily defined for this study as concentration levels below 1 atom percent, has always been considered problematic for analytical electron microscopy (AEM) with energy dispersive x-ray spectrometry (EDS) and electron energy loss spectrometry (EELS). In a landmark study of various microanalysis techniques, Wittry evaluated the influence of various instrumental factors (source brightness, detection efficiency, accumulation time) and physical factors (cross section, peak-to-background) upon detection limits. Although the ionization cross section, fluorescence yield, and collection efficiency favor EELS over EDS, the peak-to-background ratio of EELS spectra is much lower than that of EDS spectra, leading Wittry to suggest that the limit of detection should be 0.1 percent for EDS and 1 percent for EELS for practical measurement conditions. Recent developments in parallel detection EELS (PEELS) indicate that a re-evaluation of the situation for trace constituent determination is needed for those elements characterized by "white line" resonance structures at the ionization edge.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

In Situ Analysis of Surface Contaminant Desorption during Low-Temperature Silicon Substrate Cleaning using Reflection Electron Energy Loss Spectrometry

1992 ◽  
Vol 259 ◽  
Author(s):  
Selmer S. Wong ◽  
Shouleh Nikzad ◽  
Channing C. Ahn ◽  
Aimee L. Smith ◽  
Harry A. Atwater
Keyword(s):  
Low Temperature ◽  
Energy Loss ◽  
Electron Energy ◽  
Core Loss ◽  
Temperature Dependent ◽  
Electron Energy Loss Spectrometry ◽  
Analysis Technique ◽  
Chemical Analysis Technique ◽  
Electron Energy Loss

ABSTRACTWe have employed reflection electron energy loss spectrometry (REELS), a surface chemical analysis technique, in order to analyze contaminant coverages at the submonolayer level during low-temperature in situ cleaning of hydrogen-terminated Si(100). The chemical composition of the surface was analyzed by measurements of the C K, O K and Si L2,3 core loss intensities at various stages of the cleaning. These results were quantified using SiC(100) and SiO2 as reference standards for C and O coverage. Room temperature REELS core loss intensity analysis after sample insertion reveals carbon at fractional monolayer coverage. We have established the REELS detection limit for carbon coverage to be 5±2% of a monolayer. A study of temperature-dependent hydrocarbon desorption from hydrogen-terminated Si(100) reveals the absence of carbon on the surface at temperatures greater than 200°C. This indicates the feasibility of epitaxial growth following an in situ low-temperature cleaning and also indicates the power of REELS as an in situ technique for assessment of surface cleanliness.

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