Electron Probe X-Ray Analysis of Nanofilms at Off-Normal Incidence of the Electron Beam

2018 ◽  
Vol 54 (14) ◽  
pp. 1417-1420
Author(s):  
S. A. Darznek ◽  
V. B. Mityukhlyaev ◽  
P. A. Todua ◽  
M. N. Filippov
Keyword(s):  
Electron Beam ◽  
Electron Probe ◽  
Normal Incidence ◽  
X Ray

Recent Developments in the Study of Grain Boundary Segregation by Wavelength Dispersive X-Ray Spectroscopy (WDS)

2011 ◽  
Vol 309-310 ◽  
pp. 39-44
Author(s):  
Pawel Nowakowski ◽  
Frédéric Christien ◽  
Marion Allart ◽  
René Le Gall
Keyword(s):  
Electron Beam ◽  
Fracture Surface ◽  
Grain Boundary ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Boundary Segregation ◽  
Normal Incidence ◽  
Grain Boundary Segregation ◽  
X Ray ◽  
Recent Developments

It was recently shown [1] that EMPA-WDS (Electron Probe MicroAnalysis by Wavelength Dispersive X-ray Spectroscopy) can be used to detect and to accurately quantify monolayer surface and grain boundary segregation. This paper presents the last developments of this application. It focuses on the measurement of sulphur grain boundary segregation in nickel on fractured surfaces. A special attention was paid to the quantification of the sulphur coverage, taking into account the non-normal incidence of the electron beam on a fracture surface. Sulphur grain boundary segregation kinetics was measured at 750°C in nickel to document the quantitative possibilities of the technique.

Compositional imaging in the Electron Microscope

1991 ◽  
Vol 49 ◽  
pp. 2-3
Author(s):  
C. E. Lyman
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Electron Microscope ◽  
Data Collection ◽  
Electron Probe ◽  
Compositional Data ◽  
Fine Scale ◽  
Bulk Specimen ◽  
Beam Position ◽  
X Ray

Imaging of elemental distributions on a fine scale is one of the triumphs of electron microscopy. Compositional imaging frees the operator from the necessity of making decisions about which features contain the elements of interest. Elements in unexpected locations, or in unexpected association with other elements, may be found easily without operator bias as to where to locate the electron probe for compositional data collection. This technique may be applied to bulk or thin specimens using a variety of composition-sensitive signals as shown in Figure 1.Cosslett and Duncumb obtained the first such compositional image in an electron microprobe modified to scan the electron beam and collect a characteristic x-ray signal as a function of beam position. Early images of this type were called x-ray “dot maps” and provided a qualitative indication of the location of elements on a flat polished bulk specimen to a spatial resolution of about 1 μm.

The X-Ray Spectrographic Analysis of Thin Films by the Milliprobe Technique

1961 ◽  
Vol 5 ◽  
pp. 512-515 ◽  
Author(s):  
Robert D. Sloan
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Electron Probe ◽  
Spectrographic Analysis ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Bulk Production

AbstractFrequently it is desirable to perform an X-ray spectrographic analysis on an area of a specimen which is considerably smaller than that normally irradiated in bulk-production spectrographs. Ideally, one would turn to an electron-beam microanalyzer for this type of analysis. Unfortunately, there are few of us who can justify the expenditure necessary to equip our laboratories with this instrument. Therefore, a compromise measure has been arrived at which permits the analyst to examine an area many magnitudes smaller than that obtainable from production spectrographs and many magnitudes less expensive than that encountered in electron-probe microanalyzer instrumentation.

Characteristic and Continuum Fluorescence in Electron Beam X-ray Microanalysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 562-563
Author(s):  
C.E. Nockolds
Keyword(s):  
Electron Beam ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Mathematical Framework ◽  
X Rays ◽  
Correction Procedure ◽  
X Ray ◽  
Exponential Term ◽  
Accurate Expression ◽  
Original Formula

Of the different aspects of electron probe microanalysis(EPMA)which were studied by Castaing during his doctorate the work on characteristic x-ray fluorescence was the most definitive. In his thesis, which was completed in 1951, Castaing established the physical and mathematical framework for a correction procedure for fluorescence which is essentially still used in EPMA today. Much of the effort since then has been in refining and improving the accuracy of the correction and extending the scope of the correction to a wider range of specimen types. The Castaing formula was developed for the case of a K x-ray from element A being excited by a K xray from element B (K-K fluorescence) and in 1965 Reed extended the range of the correction by including the K-L, L-L and L-K interactions. In the same paper Reed also introduced the expression from Green and Cosslett for the calculation of K intensities, which was believed to be more accurate than the expression used by Castaing. The original formula included a somewhat unrealistic exponential term to allow for the depth of the production of the primary x-rays and a number of workers have tried replacing this term with a more accurate expression, however, in general this has led to only small changes in the final correction. Reed also simplified the formula in order to make the calculation easier in the days before fast computers; in particular he replaced the jump ratio variable by two constants, one for the K-shell and one for the L-shell. Much later Heinrich showed that this simplification was no longer necessary and that the jump ratio could in fact be calculated directly.

Improving the Analtical Accuracy in the Analysis of Particles by Employing Low Voltage Analysis:

2000 ◽  
Vol 6 (S2) ◽  
pp. 924-925
Author(s):  
JA Small ◽  
JT Armstrong
Keyword(s):  
Electron Beam ◽  
Electron Probe ◽  
Low Voltage ◽  
X Rays ◽  
Relative Uncertainty ◽  
Particle Volume ◽  
X Ray ◽  
Uncertainty Estimates ◽  
Corrected Data ◽  
Particle Geometry

The energy of the electron beam, in conventional electron probe microanalysis, is generally in the range of 15-25 keV which provides the necessary overvoltage to excite efficiently the K and L x-ray lines for elements with atomic numbers in the range of about 5-83. One of the primary microanalytical methods for obtaining compositional information on particles is X-ray analysis in the electron probe and these same voltage criteria have been applied to the procedures developed for this purpose. The main difference in analytical procedures for bulk samples and particles is that corrections have to be applied to the particle k-ratios or calculated compositions to compensate for: 1) the penetration or scattering of electrons out of the particle volume and 2) variations in the absorption due to particle geometry of x-rays less than about 3 keV. In general, particle corrections improve the accuracy and reduce the relative uncertainty estimates from several tens of percent for uncorrected data to about 10% for corrected data.

scholarly journals Исследование контаминационной пленки, формирующейся под действием электронного пучка

2019 ◽  
Vol 89 (9) ◽  
pp. 1412
Author(s):  
К.Н. Орехова ◽  
Ю.М. Серов ◽  
П.А. Дементьев ◽  
Е.В. Иванова ◽  
В.А. Кравец ◽  
...  
Keyword(s):  
Electron Beam ◽  
Absorption Coefficient ◽  
Electron Probe ◽  
Film Formation ◽  
Emission Lines ◽  
X Ray ◽  
Characteristic Emission ◽  
Carbon Coated ◽  
Hydrocarbon Film

During the study of materials on electron probe devices in the field of the electron beam, a contamination hydrocarbon film is formed, which influences the results of experiments. In this paper, we studied the effect of a contamination film formed on carbon-coated dielectric samples on the intensity of cathodoluminescence and X-ray characteristic emission lines. The absorption coefficient of the film for the visible and UV ranges was determined. The mechanism of film formation for various parameters of the electron beam is discussed.

The measurement of the fluorescence of Si K x-rays by Au M x-rays

1990 ◽  
Vol 48 (2) ◽  
pp. 198-199
Author(s):  
John A. Small ◽  
Scott A. Wight ◽  
Robert L. Myklebust ◽  
Dale E. Newbury
Keyword(s):  
Electron Beam ◽  
Electron Probe ◽  
Primary Electron ◽  
Characteristic Line ◽  
X Rays ◽  
Limited Information ◽  
Primary Electron Beam ◽  
X Ray ◽  
Image Position ◽  
Critical Excitation

The characteristic fluorescence correction is used in electron probe microanalysis to account for the x-ray intensity excited in element “a” by the x-rays from the characteristic line of another element, “b”, in the sample. Since the excited intensity is not generated by the primary electron beam, it is necessary to apply the fluorescence correction for quantitative elemental analysis. This correction can be significant particularly when element “b” is a major component of the sample and the characteristic line for element “b” is slightly higher in energy than the critical excitation energy for the excited line of element “a”.The fluorescence correction, which is used in the various analytical programs, is described in equation 1.where I'*fa/I'*pa is the ratio of the emitted “a” intensity excited by “b” x-rays to the emitted intensity excited by the primary electron beam. The various parameters in this equation are accurately known for the K x-ray lines, but only very limited information is available for the M x-ray lines.

Electron Probe Microanalysis of REE in Eudialyte Group Minerals: Challenges and Solutions

2015 ◽  
Vol 21 (5) ◽  
pp. 1096-1113 ◽  
Author(s):  
Petya Atanasova ◽  
Joachim Krause ◽  
Robert Möckel ◽  
Inga Osbahr ◽  
Jens Gutzmer
Keyword(s):  
Electron Beam ◽  
Electron Probe Microanalysis ◽  
Inductively Coupled Plasma ◽  
Electron Probe ◽  
Beam Diameter ◽  
Eudialyte Group ◽  
X Ray ◽  
Inductively Coupled ◽  
Individual Calibration ◽  
Plasma Mass Spectrometry

AbstractAccurate quantification of the chemical composition of eudialyte group minerals (EGM) with the electron probe microanalyzer is complicated by both mineralogical and X-ray-specific challenges. These include structural and chemical variability, mutual interferences of X-ray lines, in particular of the rare earth elements, diffusive volatility of light anions and cations, and instability of EGM under the electron beam. A novel analytical approach has been developed to overcome these analytical challenges. The effect of diffusive volatility and beam damage is shown to be minimal when a square of 20×20 µm is scanned with a beam diameter of 6 µm at the fastest possible speed, while measuring elements critical to electron beam exposure early in the measurement sequence. Appropriate reference materials are selected for calibration considering their volatile content and composition, and supplementary offline overlap correction is performed using individual calibration factors. Preliminary results indicate good agreement with data from laser ablation inductively coupled plasma mass spectrometry demonstrating that a quantitative mineral chemical analysis of EGM by electron probe microanalysis is possible once all the parameters mentioned above are accounted for.

Methods to quantify silver in autoradiographs

1980 ◽  
Vol 238 (3) ◽  
pp. H414-H422
Author(s):  
D. L. Fry ◽  
A. J. Tousimis ◽  
T. L. Talbot ◽  
S. J. Lewis
Keyword(s):  
Electron Beam ◽  
Current Density ◽  
Electron Probe ◽  
Beam Current ◽  
Silver Concentration ◽  
Electron Beam Current ◽  
Beam Size ◽  
X Ray ◽  
Small Variance ◽  
Arterial Tissue

The developed silver in specially prepared photographic films (PF) and autoradiographs (AR) of radiolabeled arterial tissue was quantified by direct grain counting (GC), microdensitometry (OD), and by electron probe X-ray microanalysis (EPA). The EPA data was proportional to the OD data with a very small variance. The GC data increased with the EPA data, but showed a large variance. The EPA signal was shown 1) to be reproducible even after multiple traverses across the specimen, 2) to be directly proportional to the electron beam current and emulsion silver concentration, and 3) to be insensitive to a) beam size, b) current density, c) energy above 17 keV, or d) nonuniformities in the thickness of the conductive coating on the specimen.

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