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Organization of hydrogen energy technologies training No. ESF/2004/2.5.0-K01-045 Main organization - Lithuanian Energy Institute Partner - Vytautas Magnus University.
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Organization of hydrogen energy technologies training No. ESF/2004/2.5.0-K01-045 Main organization - Lithuanian Energy Institute Partner - Vytautas Magnus University
I was attending in training program on EDX measurements technique and Profilometry analysis of the experimental results in the Metallurgic Physics Laboratory, in Poitiers University, France. 2005.10.02 - 2005.10.31
Outline of the presentation: How EDX Works Profilometer effect Glancing angle XRD measurements Discussions
How EDX Works (1) When an incident electron beam hits atoms of the sample, secondary and backscattered electrons can be emitted from the sample surface. These are not the only signals emitted from the sample.
How EDX Works (2) For instance, if the inner shell (the K shell) electron of an iron atom is replaced by an L shell electron, a 6400 eV K alpha X-ray is emitted from the sample
How EDX Works (3) Or, if the innermost shell (the K shell) electron of an iron atom is replaced by an M shell electron, a 7057 eV K beta X-ray is emitted from the sample.
How EDX Works (4) Or, if the L shell electron of an iron atom is replaced by an M shell electron, a 704 eV L alpha X-ray is emitted from the sample.
How EDX Works (5) An EDX Spectrum of Iron would have three peaks; An L alpha at 704 eV, a K alpha at 6400 eV, and a K Beta at 7057 eV.
How EDX Works (6) The X-rays are emitted from a depth equivalent to how deep the secondary electrons are formed. Depending on the sample density and accelerating voltage of the incident beam, this is usually from 1/2 to 2 microns in depth.
How EDX Works (7) The spectrum is of a high temperature nickel based alloy composed of nickel, chromium, iron, manganese, titanium, molybdenum, silicon, and aluminium.
PROFILOMETRY (1) A profile is, mathematically, the line of intersection of a surface with a sectioning plane which is (ordinarily) perpendicular to the surface. It is a two-dimensional slice of the three-dimensional surface. Almost always profiles are measured across the surface in a direction perpendicular to the lay of the surface.
PROFILOMETRY (2) • The average roughness, Ra, is an integral of the absolute value of the roughness profile. It Is the shaded area divided by the evaluation length, L. • Ra is the most commonly used roughness parameter.
PROFILOMETRY (3) The more complicated the shape of the surface we want and the more critical the function of the surface, the more sophisticated we need to be in measuring parameters beyond Ra.
PROFILOMETRY (4) Measurement Display Range: 200 Å to 655,000 ÅVertical Resolution: 5 ÅScan Length: 50 microns to 30 mmScan Speed Ranges: Low (50 sec/scan), Medium (12.5 sec/scan), High (3.12 sec/scan) Leveling: Manual, 2 point programmable or cursor levelingStylus Tracking Force: adjustable from 10 mg to 50 mg (0.1 mN to 0.4 milliNewtons)Maximum Sample Thickness: 20 mm (0.75")Sample Stage Diameter: 127 mm (5")Sample Stage Translation (from center): X axis = +/- 10 mm; Y axis = + 10 mm/- 70 mm Sample Stage Rotation: continuous 360 degMaximum Sample Weight: 0.5 kg (1 lb)Warm-up Time: 15 minutes for maximum stability
Comparison of high and low thickness samples Sample preparation conditions
Comparison of high and low thickness samples 2. Deposited thickness measured trough the step - 0,8653 μm 3. Deposited thickness measured trough the step - 0,1486 μm
Comparison of high and low roughness samples Sample preparation conditions
High roughness sample 1. Roughness of deposit in the corner of the sample scanning interval 100 - 1600 mikrometro is equal 0,4634 μm
Low roughness sample 1. Roughness of deposit in the corner of the sample scanning interval 0 - 1000 μm is equal 0,0063 μm 2. Roughness deposit in the centre of the sample scanning interval 1000-2000 μm is equal 0,0027 μm 3. Roughness deposit in the corner of the sample scanning interval 500 - 2000 μm is equal 0,0031 μm
Discussion Steps of the scanning sample: 0 – 400 deposit; accumulation of deposit; step (1500); substrate (1600-2000) In optical microscope we can see that there is rise and there is no perpendicular corner. The thickness of the deposit in this area is about 1 μm ?We can see two steps it seems that everything concentrates in the corner of the deposit? And how it can be that our deposit (0-1600) is lower than our substrate (1600-2000)?
Discussion Its seen three shells : From 0-730 μm there is deposit ; step in the interval 730-1062 μm Before the second step in the interval 1198 - 1362 there is rise witch height is 0.6 μm ; Before the third step, starts from 1474 μm there is rise witch height is 0.5 μm . ?Is it possible that it happens because - when our sample is on holder in the corners the particles hit the holder losing their energy and then concentrate between the sample and the holder? It seems that our holder is like a barrier for particle motion and because of this we see the rises.
Discussion In this case we can see that our deposit is lower then the substrate and it seems that it goes into substrate
EDX Sandia Si 171 Sample preparation conditions Percentage of materials in all scanning points.
EDX Sandia Si 153H Sample preparation conditions Mg and Al percentage separate in all scanning points
EDX Sandia Si 160H Sample preparation conditions Al percentage separate in all scanning points
EDX Sandia Q 190 Sample preparation conditions Percentage of materials in all scanning points
EDX Sandia Q 190 Mg and Al percentage separate in all scanning points
EDX Sandia Q 190 Ni percentage separate in all scanning points
Discussion From EDX analyze of the samples SandiaSi 171 and Sandia Si 153H we saw that percentage of analyzed materials in one corner of the sample is lower then in another. ? why.