Slide 1: Diffraction in micro-XRF: A tool, rather than a complication?
WEBINAR Diffraction in micro-XRF A tool, rather than a complication? Christian Hirschle, Falk Reinhardt
Slide 2: The speakers
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? The speakers Dr. Christian Hirschle Application Scientist, Bruker Nano Analytics, Berlin, Germany Falk Reinhardt Senior Application Scientist, Bruker Nano Analytics, Berlin, Germany © 2025 Bruker Innovation with Integrit
Slide 3: Agenda
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Agenda 1 Introduction to diffraction in micro-XRF 5 X-ray topographical application of micro-XRF 2 Energy dispersive Laue mapping (EDLM): Theory 6 Summary and Q&A session 3 Energy dispersive Laue mapping (EDLM): Investigating or
Slide 4: Introduction to micro-XRF
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Introduction to micro-XRF 1 3 Micro-XRF with lens 2 Small-spot XRF with collimator © 2025 Bruker Innovation with Integrity | | 4
Slide 5: Intensity distribution maps
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Intensity distribution maps Maps per default show the intensity distribution of detected radiation in specific energy regions of interest (ROI). Background or overlap corrections may be applied. High K The ROI for an eleme
Slide 6: Intensity distribution maps
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Intensity distribution maps When an element is below the limit of detection or homogeneously distributed, the intensity in the ROI will barely change Maps will show random scatter from point to point, white noise. The Ge m
Slide 7: Intensity distribution maps
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Intensity distribution maps Spectra from bright regions in Ge map were extracted. There are peaks in the Ge ROI. However, compared to regular Ge-Kα Ge fluorescence peaks, they are centered at different energies, do not 1 hav
Slide 8: Diffraction: Bragg equation
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Diffraction: Bragg equation How does diffraction happen? X-rays get scattered on the electron density; angle of incidence θ with planes of translation lattice; plane spacing d. Angle of incidence is equal to angle of reflectio
Slide 9: Diffraction: Why multiple planes at once?
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Diffraction: Why multiple planes at once? X-ray tube excitation spectrum is continuous in energy range. For a given direction of incident radiation, many combinations of d, θ and λ fulfill Bragg‘s law! Excitation spectrum, R
Slide 10: Diffraction: Why multiple planes at once?
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Diffraction: Why multiple planes at once? Micro-XRF spectra often exhibit multiple diffraction peaks due to “white” X-rays used for excitation, large detectors, and beam divergence. diffraction peaks Simulated diffraction
Slide 11: How to get rid of diffraction peaks: Filters
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? How to get rid of diffraction peaks: Filters Diffraction relies on specific wavelengths of primary radiation for a given crystal structure/orientation. Blocking this radiation before it reaches a sample via a primary beam filt
Slide 12: EDLM: Introduction
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM : Introduction SiC rotating horizontally in an M4 TORNADO PLUS. SiC wafer. Hexagonal, (001) pointing up. One detector, AMS 500, 120 s per measurement. We can visualize changing crystal orientation by investigating diffrac
Slide 13: EDLM: NdGaO3, twinning
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: NdGaO3, twinning Perovskite-type NdGaO3: widely used as substrate for epitaxial growth of a variety of thin films. Interface/strain crucial for film properties (ferroelectricity, magnetism…). Changing orientation of
Slide 14: EDLM: NdGaO3, twinning
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: NdGaO3, twinning Same Map, ROI on diffraction peaks: Energy-dispersive Laue mapping (EDLM). → The sample is twinned; there are two types of orientation within the sample. EDLM reveals that the sample has two twin domai
Slide 15: EDLM: Sr2DyNbO6
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Sr2DyNbO6 EDLM shows sudden changes to orientation, twinning following rotation during growth, as well as striations within the domains. Indications that rotation speed may have been too high? © 2025 Bruker Innovatio
Slide 16: EDLM: Continuous patterns?
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Continuous patterns? Surface-polished, flat Kyanite (Al2[O|SiO4]) sample. Si P Chemically quite homogenous; one apatite inclusion close to center. EDLM shows distinct zones, but transitions appear gradual without sharp b
Slide 17: EDLM: Continuous patterns?
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Continuous patterns? Spectra were extracted for ~0.9 mm wide regions from left to right on the surface. Diffraction pattern changes continuously, rather than abruptly Grain orientation changes continuously! Pos 1 Pos 2
Slide 18: EDLM: Garnet from Zillertal
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Garnet from Zillertal Data kindly provided by Universität Innsbruck, Institute of Mineralogy and Petrography EDLM is not restricted to synthetic crystals! Micro-XRF map of garnet from Zillertal provides at least three diff
Slide 19: EDLM: Correspondence to chemical information
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Correspondence to chemical information Iron in polycrystalline Si. The conspicuous pattern implies some relation with the crystal domains. © 2025 Bruker Innovation with Integrity | | 19
Slide 20: EDLM: Correspondence to chemical information
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Correspondence to chemical information The domain map is perfectly in line with the Fe distribution. During crystal growth, the inclusion of many foreign elements – traces at that time – is energetically disadvantageou
Slide 21: EDLM: Correspondence to chemical information
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Correspondence to chemical information Ca you would usually try to avoid in Si melt. It can be added to control crystal formation. In this case, one of the additives formed “horizons”. © 2025 Bruker Innovation with I
Slide 22: EDLM: Correspondence to chemical information
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Correspondence to chemical information © 2025 Bruker Innovation with Integrity | | 22
Slide 23: EDLM: Aluminium and mechanical properties
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Aluminium and mechanical properties Almost pure aluminium Apparently slow cooling → large domains In the center many small domains ... Towards the outside some prevail and the grains get larger. Note: in the sidewall
Slide 24: EDLM: Aluminium and mechanical properties
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Aluminium and mechanical properties Different 7xxx Aluminium alloys with very similar composition. The main difference here is the crystal domain size. 7xxx Aluminium alloys are used in space/aerospace applications, wh
Slide 25: EDLM: Archaeological objects
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Archaeological objects Fe P Fragments of a gilded dagger from the 14th century cast in epoxy. Au + Hg The gilding reveals that the central fragment is rotated against its initial orientation. © 2025 Bruker Innovation w
Slide 26: EDLM: Archaeological objects
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Archaeological objects Domain map of the fragments. The center fragment rotated for this comparison. Clearly domains are larger on the edges → this material could be softer than the core, which is ... surprising Si
Slide 27: EDLM: Degenerate orientations
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Degenerate orientations X-ray X-ray Can we see any change in orientation in the data? No. θ1 θ2 Rotation around the direction of the primary beam does not affect the angle of incidence This rotation does not change ene
Slide 28: EDLM: Visualizing crystal quality
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Visualizing crystal quality (Mg,Zr):SrGa12O19 Substrate for epitaxial growth of hexaferrites (magnetoplumbites). Growth by Czochralski method. Doped with Mg and Zr for better growth properties. Regular analysis by mi
Slide 29: EDLM: Visualizing crystal quality
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? PSG: 6/mmm EDLM: Visualizing crystal quality Material is a single crystal. However: EDLM of just a single selected [010] diffraction peak reveals information about structural quality! [100] micro-XRF rocking curve imaging (8.25
Slide 30: EDLM: Visualizing crystal quality
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? EDLM: Visualizing crystal quality Variations in quality translate to changing secondary Why do intensities change in EDLM of a single crystal? extinction. Dislocations tend to agglomerate impurity elements. More varying la
Slide 31: Micro-XRF for X-ray topography
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Micro-XRF for X-ray topography X-ray topography: Intensity distribution imaging of diffracted X-rays. Defects (inclusions, dislocations, …) cause local lattice strain, modulating diffracted intensity (fine structure of a Bragg p
Slide 32: Micro-XRF for X-ray topography
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Micro-XRF for X-ray topography Lang topography Dislocations in high quality silicon can be visualized! 5 mm Results very similar to those from Lang topography can be acquired. micro-XRF, (2 2 4) reflection Strong energy de
Slide 33: Micro-XRF for X-ray topography
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Micro-XRF for X-ray topography In standard XRT techniques: Curved surfaces problematic. Much smaller problem in micro-XRF due to focused convergent beam! In micro-XRF: dislocations can be visualized in curved surfaces, dislo
Slide 34: Aperture management and diffraction peaks
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Aperture management and diffraction peaks Consequences of using an aperture: No aperture Increased depth of field, AMS1000 AMS500 Reduced width of diffraction peaks, Loss of intensity. This example, 6 keV to 18 keV: loss o
Slide 35: Summary
DIF F RACTION IN M ICRO-X RF – A TOOL, RATH ER TH AN A COM P LICATION ? Summary Data from micro-XRF measurements on crystalline samples contain information beyond chemistry. Diffracted radiation can hit detectors with their energy and intensity depending on, among others, the structure type, lattice
Slide 36: Thank you!
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