X-Ray Diffraction

  • What we do

    From the local to global average structure, we support structure investigations of materials from crystalline nanomaterials to macroscopic single crystals at ambient and non-ambient conditions.

  • What we do

    From the local to global average structure, we support structure investigations of materials from crystalline nanomaterials to macroscopic single crystals at ambient and non-ambient conditions.

X-ray Diffraction

X-rays are scattered by the electronic shells of the atoms. Regular periodic arrangement of the atoms leads to sharp diffraction peaks described by the Bragg-equation, all deviations from the periodicity gives rise to the so-called diffuse scattering. Bragg-scattering can be evaluated by Rietveld-refinements. With adapted measurement techniques the sample’s diffuse scattering can be evaluated as well (Total-Scattering).

What kind of result do I get?

The measurement result is a diffractogram, which is used to determine the phase composition of the sample. In the case of well crystalline samples, Rietveld refinements use the Bragg scattering information to refine an average structure model. Total scattering data can be evaluated using either models based on statistical ensembles of crystallites (genetic-algorithms) or large super-cells of an average structure model in which disorder is included on every atomic position using Reverse-Monte-Carlo methods.

Area responsible

Prof. Dr. Thorsten M. Gesing

Application Scientist

Dr. Lars Robben
X-ray diffraction and SEM lab head
Radiation protection office @ CKfS
E-mail: lrobbenprotect me ?!uni-bremenprotect me ?!.de

Our key instruments

Stoe Stadi MP
Powder X-ray diffractometer

  • Transmission and reflection geometry with Mo radiation
  • Measurements from 10 K to 1800 K
  • Total-scattering pre-measurements for applications at large-scale research facilities
mehr

Bruker D8 Venture
4-circle diffractometer

  • Monochromatic Mo Kalpha radiation
  • 2D detector
  • Measurements from 170 K to 1270 K
mehr

Bruker D8 Advance
Cu and Mo X-ray powder diffractometer

  • Bragg-Brentano and transmission geometry
  • Measurements from 100 K to 1500 K
mehr

More available instruments

More information about the instrumentation available at MAPEX and MAPEX-CF can be found in the Instrument Database of the MAPEX Center for Materials and Processes.

A click on the logo will lead you to the database.

Research Highlights

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X-Ray Diffraction| Spectroscopy|

Nano-crystalline precursor formation, stability, and transformation to mullite-type visible-light photocatalysts

Thorsten M. GesingM. Mangir Murshed, Selina Schuh, Oliver Thüringer, Konrad Krämer, Tim Neudecker, Cecilia B. Mendive & Lars Robben 

Journal of Materials Science (2022), 57, 19280-19299

https://doi.org/10.1007/s10853-022-07854-w

A new precursor for the formation of mullite-type visible-light…


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X-Ray Diffraction|

Revisiting the Growth of Large (Mg,Zr):SrGa12O19 Single Crystals: Core Formation and Its Impact on Structural Homogeneity Revealed by Correlative X-ray Imaging

Christo Guguschev, Carsten Richter, Mario Brützam, Kaspars Dadzis, Christian Hirschle, Thorsten M. Gesing, Michael Schulze, Albert Kwasniewski, Jürgen Schreuer, and Darrell G. Schlom

Crystal Growth and Design (2022), 22, 4, 2557–2568

https://doi.org/10.1021/acs.cgd.2c00030

We demonstrate the…


X-Ray Diffraction|

Halide-sodalites: thermal expansion, decomposition and the Lindemann criterion

Marius Wolpmann, Lars Robben and Thorsten M. Gesing

Zeitschrift für Kristallographie - Crystalline Materials (2022), 237, 1-3

https://doi.org/10.1515/zkri-2022-0004

Twelve cubic sodalites |Na8X2|[T1T2O4]6 (T1 = Al3+, Ga3+; T2 = Si4+, Ge4+; X = Cl−, Br−, I−) were examined using high-temperature…


Aktualisiert von: MAPEX