MLZ is a cooperation between:

Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Geesthacht> Helmholtz-Zentrum GeesthachtForschungszentrum Jülich> Forschungszentrum Jülich
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Lichtenbergstr.1
85748 Garching

SPODI

High resolution powder diffractometer

SPODI SPODI


The high resolution powder diffractometer SPODI is designed for structure solution and Rietveld refinement of structural parameters on crystalline powders. The instrument is characterised by a very high monochromator take-off angle of 155° (standard configuration). Optionally, a take-off angle of 135° is available.

The detector array consists of 80 3He position sensitive detector tubes (300 mm active height) with fixed Soller collimators of 10’ horizontal divergence. The multidetector of SPODI spans an angular range of 2θ = 160°. Each detector covers 2° corresponding to 160°/ 80 detectors. Therefore the data collection is performed via stepwise positioning of the detector array to obtain a diffraction pattern of the desired step width (typically 2°/ 40 steps resul­ting in Δ(2θ) = 0.05°).

The two-dimensional raw data are evaluated to provide diffraction patterns corresponding to different detector heights ranging from 10 mm to 300 mm and variable detector height, accounting for vertical beam divergence effects. Thus, asymmetric broadenings at quite low and high scattering angles are overcome, while the full detector height in the medium 2θ regime can be used [1].

Various sample environmental devices enable the characterisation of materials under special conditions: A rotatable tensile rig allows in-situ studies under tensile stress, compression stress or torsion while the load axis can be oriented with respect to the scattering plane. A potentiostat for charging/discharging of Lithium ion batteries is available as well as a device to apply high electric fields on ferroelectrics.

[1] Hoelzel, M. et al., Nucl. Instr. A 667, 32-37 (2012).

Typical Applications
  • Determination of complex crystal and magnetic structures
  • Structural evolutions and phase transformations under various environmental conditions.
  • Static and thermal disorder phenomena
Research Areas
  • Ionic conductors
  • Materials for lithium ion batteries
  • Ferroelectrics, multiferroics
  • Hydrogen storage materials
  • Shape memory alloys
  • Superalloys
  • Correlated electron systems
  • Superconductors
  • Minerals
Sample Environment

Standard sample environment of FRM II

  • Closed cycle cryostat 3 – 550 K
    (with 3He insert: Tmin = 500 mK)
  • Vacuum high temperature furnace
    Tmax = 1900°C
  • Cryomagnet
    Bmax at SPODI: 5 T
  • Sample changer (six samples, ambient temperature)

Special sample environment

  • Rotatable tensile rig
    Fmax = 50 kN, Mmax = 100 Nm
  • Device for electric fields
    Vmax = 35 kV
  • Potentiostat for electrochemical treatment of materials VMP3 and SP240

Technical Data

Monochromator

  • Ge(551) wafer stack crystals
  • standard configuration: take-off angle 155°
    • Ge(551): 1.548 Å
    • Ge(331): 2.536 Å
    • Ge(711): 1.111 Å

Collimation

  • α1 ≈ 20’ (neutron guide)
  • α2 = 5’,10’, 20’, 25’ nat. (for 155°)
  • α2 = 10’, 20’, 40’ nat. (for 135°)
  • α3 = 10’

Detector array

  • 80 position-sensitive 3He tubes,
    • angular range 2θ = 160°,
    • effective height: 300 mm

Instrument Scientists

Dr. Markus Hölzel
Phone: +49 (0)89 289-14314
E-Mail:

Dr. Anatoliy Senyshyn
Phone: +49 (0)89 289-14316
E-Mail:

Dr. Volodymyr Baran
Phone: +49 (0)89 289-14373
E-Mail:

Dr. Martin J. Mühlbauer
Phone: +49 (0)89.289-14373
E-Mail:

SPODI
Phone: +49 (0)89 289-14826

Operated by

KIT
TUM

Publications

Find the latest publications regarding SPODI in our publication database iMPULSE:

impulse.mlz-garching.de

Citation of the instrument

Heinz Maier-Leibnitz Zentrum. (2015). SPODI: High resolution powder diffractometer. Journal of large-scale research facilities, 1, A5. http://dx.doi.org/10.17815/jlsrf-1-24

For citation please always include the DOI.

Gallery

SPODI
SPODI
© W. Schürmann, TUM
Corundum reference sample
Corundum reference sample

Figure 1: Two-dimensional data set of a corundum reference sample. The straight white lines bound a detector height of 150 mm and the detector height 0 denotes the central line of the detector. The dotted white lines encompass the data used in the “300 mm – variable height” data set.

MLZ is a cooperation between:

Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Geesthacht> Helmholtz-Zentrum GeesthachtForschungszentrum Jülich> Forschungszentrum Jülich