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-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).

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.

Prof. Dr. Thorsten M. Gesing

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

Bruker D8 Venture
4-circle diffractometer

Monochromatic Mo K_alpha radiation
2D detector
Measurements from 170 K to 1270 K

Bruker D8 Advance
Cu and Mo X-ray powder diffractometer

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

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.

Research Highlights

$Effect of intrinsic heat treatment on the precipitate formation of X40CrMoV5–1 tool steel during laser-directed energy deposition: A coupled study of atom probe tomography and in situ synchrotron X-ray diffraction pic$

3D Materials Analytics| Correlated Workflows| X-Ray Diffraction| Electron Microscopy| 15.01.2025

Effect of intrinsic heat treatment on the precipitate formation of X40CrMoV5–1 tool steel during laser-directed energy deposition: A coupled study of atom probe tomography and in situ synchrotron X-ray diffraction

Antonio Carlos de F. Silveira, Lisa T. Belkacemi, Pedro José de Castro, Marco Schowalter, Rainer Fechte-Heinen, Jérémy Epp

Acta Materialia 283 (2025): 120488

https://doi.org/10.1016/j.actamat.2024.120488

Additively manufactured components are generally heat treated to remove the undesired…

Materials Modelling| X-Ray Diffraction| Spectroscopy| 01.11.2024

Synthesis, structural and spectroscopic characterization of defect-rich forsterite as a representative phase of Martian regolith

Muchammad Izzuddin Jundullah Hanafi, Lorenzo Bastonero, Mohammad Mangir Murshed, Lars Robben, Wilke Dononelli, Andrea Kirsch, Nicola Marzari, Thorsten M. Gesing

IUCrJ 11 (2024): 977-990

https://doi.org/10.1107/S2052252524009722

Regolith draws intensive research attention because of its importance…

X-Ray Diffraction| Spectroscopy| 30.07.2024

Mechanochemical synthesis of (Mg₁₋ₓFeₓ)₂SiO₄ olivine phases relevant to Martian regolith: structural and spectroscopic characterizations

Izzuddin Jundullah Hanafi, M. Mangir Murshed, Lars Robben, Thorsten M. Gesing

Zeitschrift für Kristallographie - Crystalline Materials (2024)

https://doi.org/10.1515/zkri-2024-0078

To fabricate metals from the base materials for future Mars exploration, synthesis of representative olivine phases…

X-Ray Diffraction

What we do

What we do