Basic literacy in electron-excited x-ray microanalysis

1993 ◽  
Vol 51 ◽  
pp. 502-503
Author(s):  
Dale E. Newbury
Keyword(s):  
Biological Sciences ◽  
Energy Dispersive ◽  
Automation System ◽  
X Rays ◽  
Thin Sections ◽  
X Ray ◽  
Operational Characteristics ◽  
Analysis Strategy ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Electron beam x-ray microanalysis with energy dispersive x-ray spectrometry (EDS), as performed in electron probe microanalyzers (EPMA)/scanning electron microscopes (SEM) for thick specimens and analytical electron microscopes (AEM) for thin sections, is a powerful technique with wide applicability in the physical and biological sciences and technology communities. The operation of an EDS x-ray microanalysis system has been automated to the point that many users now consider EDS to be a routine tool where the results reported by the automation system are always correct Unfortunately, there are numerous pitfalls awaiting the unwary analyst. All EDS users require a basic level of literacy in x-ray microanalysis to properly interpret spectra and develop a sensible analysis strategy for their problems. This “basic literacy” includes knowledge of the factors controlling the efficiency of production of characteristic and continuum x-rays, the characteristic energies and structure of x-ray families that provide the basis for qualitative analysis, the operational characteristics of energy dispersive x-ray spectrometers, including artifacts, and the systematic procedures for qualitative and quantitative analysis.

Energy-Dispersive X-Ray Emission Spectroscopy

1970 ◽  
Vol 24 (6) ◽  
pp. 557-566 ◽  
Author(s):  
R. S. Frankel ◽  
D. W. Aitken
Keyword(s):  
Emission Spectroscopy ◽  
Energy Dispersive ◽  
New Developments ◽  
X Ray ◽  
Different Types ◽  
Recent Developments ◽  
System Requirements ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Realistic Appraisal

A review is given of recent developments in energy-dispersive x-ray emission spectroscopy, with the aim of providing both an introductory and usefully practical look at this innovative field. The review begins with the first principles of x-ray production and observation, including a brief comparison of the performance capabilities of different types of detectors, but then specializes to a major extent in solid state x-ray spectrometers, which have led to the most significant new developments and applications. Evidence is presented which suggests that we are nearing an asymptotic limit in the attainment of ever better resolution with these types of systems. Applications that have been made possible by significant improvements in system resolution are discussed, but in the context of the need for a realistic appraisal of over-all system requirements. The great advantages offered by the marriage of silicon x-ray spectrometers to scanning electron microscopes and electron microprobe analyzers are reviewed and illustrated.

Mini-Scanning Electron Miscroscope Concept

1974 ◽  
Vol 32 ◽  
pp. 406-407
Author(s):  
Donald J. Evins ◽  
Robert J. Engle
Keyword(s):  
Electron Microscope ◽  
Depth Of Field ◽  
X Ray ◽  
Rapid Scan ◽  
Operational Characteristics ◽  
Electron Microscopes ◽  
The Cost ◽  
Scanning Electron Microscopes ◽  
Large Research ◽  
Scanning Electron

The scanning electron microscope has already established itself as one of the most useful instrument developments in recent years. The SEM provides 20 times greater useful magnifications and up to 500 times greater depth of-field than the best optical microscopes. Until the introduction of the Mini-SEM concept, the cost and complexity of SEM's has limited their use primarily to large research oriented laboratories.Design features, specifications, and operational characteristics will be reviewed. The Mini-Rapid Scan with resolution of 750Å will be described, along with the Mini-SEM with resolution of 150 to 200Å. Both of these are table top scanning electron microscopes. Various specimen stage options will be illustrated. Other accessories extending the SEM's versatility will be described, such as the energy dispersive x-ray system

An Integrated System for Elemental X-Ray Analysis of Materials

1972 ◽  
Vol 16 ◽  
pp. 284-297
Author(s):  
J.C. Russ ◽  
A.O. Sandborg ◽  
M.W. Barnhart ◽  
C.E. Soderquist ◽  
R.W. Lichtinger ◽  
...  
Keyword(s):  
Low Power ◽  
Integrated System ◽  
X Rays ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Field L ◽  
Wavelength Dispersive Spectrometer ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The use of energy dispersive analysis of x-rays (EDAX method) is now well entrenched in the electron column field(l), where more scanning electron microscopes have been fitted with EDAX instrumentation than all of the conventional (wavelength-dispersive spectrometer) microprobes ever made. The principle advantage of the EDAX approach for the SEM user is the efficiency of detection, which permits its use at the low power levels of the SEM. In addition, the simultaneous analysis of the entire spectrum and the lack of focusing restrictions that permits analysis of rough samples are important advantages.

Characterization of small inclusions: SEM vs TEM, or is it even worth considering Sem?

1996 ◽  
Vol 54 ◽  
pp. 498-499
Author(s):  
Carl Blais ◽  
Gilles L’Espérance ◽  
Éric Baril ◽  
Clément Forget
Keyword(s):  
Chemical Composition ◽  
X Rays ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Micro Alloyed Steel ◽  
Steel Welds ◽  
Scanning Electron Microscopes

Inclusions of technological importance are often in the size range from 0.1 to 1 μm, These inclusions are generally too thick for EEL-spectrometry and require the use of EDS to characterize their chemical composition. Recent Monte Carlo simulations indicated that scanning electron microscopes (SEM’s) equiped with a field emission gun (FEG) might challenge transmission electron microscopes (TEM’s) for the charaterization of small inclusions, In the light of these results, we investigated the possibility of using a FEGSEM to characterize inclusions found in micro-alloyed steel welds used for arctic applications. The main setbacks of using EDS for such a task are due to the presence of small phases of unknown thicknesses, non-homogeneity of the X-ray generation volumes, variation in absorption along the path length of the X-rays, etc., Even though these problems are encoutered in both the SEM and the TEM, the relative ease of imaging the very small inclusions in TEM confers a definite advantage to this technique. Furthermore, TEM allows to obtain convergent-bearn electron diffraction patterns (CBED) which complement the chemical composition characterization, thereby allowing the unambiguous identification of the phases present (chemistry and crystal structure).

New reference and test materials for the characterization of energy dispersive X-ray spectrometers at scanning electron microscopes

2014 ◽  
Vol 407 (11) ◽  
pp. 3045-3053 ◽  
Author(s):  
Vanessa Rackwitz ◽  
Michael Krumrey ◽  
Christian Laubis ◽  
Frank Scholze ◽  
Vasile-Dan Hodoroaba
Keyword(s):  
Energy Dispersive ◽  
X Ray ◽  
Test Materials ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Development of a New Quantitative X-Ray Microanalysis Method for Electron Microscopy

2010 ◽  
Vol 16 (6) ◽  
pp. 821-830 ◽  
Author(s):  
Paula Horny ◽  
Eric Lifshin ◽  
Helen Campbell ◽  
Raynald Gauvin
Keyword(s):  
Field Emission ◽  
Beam Current ◽  
Physical Parameters ◽  
X Rays ◽  
Experimental Conditions ◽  
X Ray ◽  
Stable Regime ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

AbstractQuantitative X-ray microanalysis of thick samples is usually performed by measuring the characteristic X-ray intensities of each element in a sample and in corresponding standards. The ratio of the measured intensities from the unknown material to that from the standard is related to the concentration using the ZAF or ϕ(ρz) equations. Under optimal conditions, accuracies approaching 1% are possible. However, all the experimental conditions must remain the same during the sample and standard measurements. This is not possible with cold field emission scanning electron microscopes (FE-SEMs) where beam current can fluctuate around 5% in its stable regime. Very little work has been done on variable beam current conditions (Griffin, B.J. & Nockolds, C.E., Scanning13, 307–312, 1991), and none relating to cold FE-SEM applications. To address this issue, a new method was developed using a single spectral measurement. It is similar in approach to the Cliff-Lorimer method developed for the analytical transmission electron microscope. However, corrections are made for X rays generated from thick specimens using the ratio of the characteristic X-ray intensities of two elements in the same material. The proposed method utilizes the ratio of the intensity of a characteristic X-ray normalized by the sum of X-ray intensities of all the elements measured for the sample, which should also reduce the amplitude of error propagation. Uncertainties in the physical parameters of X-ray generation are corrected using a calibration factor that must be previously acquired or calculated. As an example, when this method was applied to the calculation of the composition of Au-Cu National Institute of Standards and Technology standards measured with a cold field emission source SEM, relative accuracies better than 5% were obtained.

X-ray Gabor holography

1995 ◽  
Vol 53 ◽  
pp. 612-613
Author(s):  
Steve Lindaas ◽  
Chris Jacobsen ◽  
Alex Kalinovsky ◽  
Malcolm Howells
Keyword(s):  
Surface Relief ◽  
Biological Imaging ◽  
Specimen Preparation ◽  
X Rays ◽  
X Ray ◽  
Water Window ◽  
Biological Objects ◽  
Transmission Imaging ◽  
Atomic Force ◽  
Electron Microscopes

Soft x-ray microscopy offers an approach to transmission imaging of wet, micron-thick biological objects at a resolution superior to that of optical microscopes and with less specimen preparation/manipulation than electron microscopes. Gabor holography has unique characteristics which make it particularly well suited for certain investigations: it requires no prefocussing, it is compatible with flash x-ray sources, and it is able to use the whole footprint of multimode sources. Our method serves to refine this technique in anticipation of the development of suitable flash sources (such as x-ray lasers) and to develop cryo capabilities with which to reduce specimen damage. Our primary emphasis has been on biological imaging so we use x-rays in the water window (between the Oxygen-K and Carbon-K absorption edges) with which we record holograms in vacuum or in air.The hologram is recorded on a high resolution recording medium; our work employs the photoresist poly(methylmethacrylate) (PMMA). Following resist “development” (solvent etching), a surface relief pattern is produced which an atomic force microscope is aptly suited to image.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

Comparison of high-angle take-off and low-angle take-off EDX detector geometry of the HF-2000 FE-TEM

1993 ◽  
Vol 51 ◽  
pp. 252-253
Author(s):  
Y. Sato ◽  
T. Hashimoto ◽  
M. Ichihashi ◽  
Y. Ueki ◽  
K. Hirose ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Field Emission ◽  
Solid Angle ◽  
Energy Dispersive ◽  
Objective Lens ◽  
X Rays ◽  
High Angle ◽  
X Ray ◽  
Detector Geometry

Analytical TEMs have two variations in x-ray detector geometry, high and low angle take off. The high take off angle is advantageous for accuracy of quantitative analysis, because the x rays are less absorbed when they go through the sample. The low take off angle geometry enables better sensitivity because of larger detector solid angle.Hitachi HF-2000 cold field emission TEM has two versions; high angle take off and low angle take off. The former allows an energy dispersive x-ray detector above the objective lens. The latter allows the detector beside the objective lens. The x-ray take off angle is 68° for the high take off angle with the specimen held at right angles to the beam, and 22° for the low angle take off. The solid angle is 0.037 sr for the high angle take off, and 0.12 sr for the low angle take off, using a 30 mm2 detector.

Analysis on Microstructure of Laser Brazing Diamond Grits with a Ni-Based Filler Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 3879-3883 ◽  
Author(s):  
Zhi Bo Yang ◽  
Jiu Hua Xu ◽  
Ai Ju Liu
Keyword(s):  
Active Element ◽  
Steel Substrate ◽  
Parameters Optimization ◽  
Interfacial Region ◽  
Filler Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cross Diffusion ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out via laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits and the filler layer were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy through parameters optimization.

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