High Spatial Resolution Low Energy Electron Beam X-ray Microanalysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 310-311
Author(s):  
I.R. Barkshire ◽  
P. Karduck ◽  
W. Rehbach ◽  
S. Richter
Keyword(s):  
Energy Performance ◽  
Beam Current ◽  
Low Energy ◽  
Advanced Materials ◽  
X Ray ◽  
Routine Basis ◽  
Low Energy Electron ◽  
Electron Microscopes ◽  
Relative Errors ◽  
Scanning Electron Microscopes

Conventionally, x-ray microanalysis on scanning electron microscopes (SEM) with energy dispersive spectrometers (EDS) has been performed with relatively high primary energies (>10 kv). for most samples this results in reasonably good separation of the generated x-ray line series from different elements enabling unambiguous identification and therefore accurate qualitative analysis. Under these circumstances it is widely accepted that quantitative analysis of polished bulk samples is possible on a routine basis with relative errors around 1-5% and detection limits of the order of 0.1%.However, in order to address the analysis requirements of new advanced materials with sub-micron features, there is growing interest in performing x-ray microanalysis at low beam energies(<5kv). this is now a more realistic goal due to the routine availability of field emission sem's which can operate with much improved beam sizes at low beam energies with sufficient beam current to perform practical microanalysis, in conjunction with the improved low energy performance of current, commercially available EDS systems.

scholarly journals Practical Issues for Quantitative X-ray Microanalysis in SEM at Low kV

2006 ◽  
Vol 14 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Peter Statham
Keyword(s):  
Quantitative Analysis ◽  
Atomic Number ◽  
Beam Current ◽  
Research Groups ◽  
X Ray ◽  
Time Scanning ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

In the three decades following Castaing's seminal thesis [1] x-ray analysis received widespread attention from research groups. By 1980, the methods and correction procedures for quantitative analysis of elements with atomic number 11 and above, using accelerating voltages between 15kV and 25kV, were well established and available in commercial instrumentation. At the time, scanning electron microscopes (SEMs) could rarely deliver high and stable beam current at much lower kV, and x-ray spectrometers had poor efficiency below lkeV so that low kV analysis received comparatively little attention.

Characterization of Multilayered Structures Using a FEGSEM and X-Ray Microanalysis

1997 ◽  
Vol 3 (S2) ◽  
pp. 463-464
Author(s):  
Raynald Gauvin ◽  
Mario Caron ◽  
Vincent Fortin ◽  
John F. Currie
Keyword(s):  
Physical Parameters ◽  
Elastic Recoil ◽  
Multilayered Structures ◽  
X Ray ◽  
Elastic Recoil Detection ◽  
Routine Basis ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Multilayer Metallization ◽  
Scanning Electron

Microelectronic processes now involve multilayer structures of different materials. It is important to control accurately the thickness and composition of these materials during their processing. The determination of these two physical parameters are usually performed by Elastic Recoil Detection (ERD), by Auger Electron Spectroscopy (AES) and Transmission Electron Microscopy (TEM). However, these techniques are not suitable for analysis on a routine basis. In this context, a quantitative procedure based on EDS X-ray microanalysis in the Scanning Electron Microscope has been developped because of its availability and its speed of analysis. However, this technique requires several measurement of K ratio taken at different voltages which is time consuming. With the advent of Field Emission Gun Scanning Electron Microscopes (FEGSEM), X-ray line scans taken at low electron beam voltage with an EDS system may be an alternative. In this paper, preliminary results using this technique on multilayered materials are presented.To investigate this characterization technique, a AlSiCu(200 nm)/TiN(95 nm)/Ti(40 nm) multilayer metallization structure deposited on Si substrate was used. EDS X-ray line scans were obtained with a Hitachi S-4500 FEGSEM coupled with a Link ISIS 300 EDS system.

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.

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.

scholarly journals Creep Failure of Reformer Tubes in a Petrochemical Plant

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1026 ◽  
Author(s):  
Abbas Bahrami ◽  
Peyman Taheri
Keyword(s):  
High Temperature ◽  
Void Coalescence ◽  
Petrochemical Plant ◽  
Creep Failure ◽  
X Ray ◽  
Carbide Phases ◽  
Electron Microscopes ◽  
Reformer Tubes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

This paper investigates a failure in HP-Mod radiant tubes in a petrochemical plant. Tubes fail after 90,000 h of working at 950 °C. Observed failure is in the form of excessive bulging and longitudinal cracking in reformer tubes. Cracks are also largely branched. The microstructure of service-exposed tubes was evaluated using optical and scanning electron microscopes (SEM). Energy-dispersive X-ray spectroscopy (EDS) was used to analyze and characterize different phases in the microstructure. The results of this study showed that carbides are coarsened at both the inner and the outer surface due to the long exposure to a carburizing environment. Metallography examinations also revealed that there are many creep voids that are nucleated on carbide phases and scattered in between dendrites. Cracks appeared to form as a result of creep void coalescence. Failure is therefore attributed to creep due to a long exposure to a high temperature.

X-ray and Low Energy Electron Induced Damage in Alkanethiolate Monolayers on Au-substrates

1997 ◽  
Vol 202 (Part_1_2) ◽  
pp. 263-272 ◽  
Author(s):  
B. Jäger ◽  
H. Schürmann ◽  
H. U. Müller ◽  
H.-J. Himmel ◽  
M. Neumann ◽  
...  
Keyword(s):  
Low Energy ◽  
Energy Electron ◽  
X Ray ◽  
Low Energy Electron
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