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Forschungszentrum Jülich> Forschungszentrum Jülich

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Lichtenbergstr.1
85748 Garching

NREX

Polarised neutron reflectometer with X-ray option

This instrument is focussed on cold neutrons. All parameters given here are valid during the current operation of FRM II. Please get in touch with the instrument team well in advance for all further details (length of experiment etc.).

Instrumentscheme N-REX Instrumentscheme N-REX

The neutron/ X-ray contrast reflectometer NREX is designed for the determination of structural and magnetic properties of surfaces, interfaces, thin films and heterostructures.

A focusing multiblade monochromator allows for measuring small area (20 mm2) samples with high polarisation in a dynamic range of six orders of magnitude. For larger samples and a non-polarized beam more than seven orders are feasible. A horizontal alignment of the sample allows for performing (a) GISANS and GIND and (b) in-situ X-ray experiments. For the latter an optional X-ray reflectometer is mounted perpendicular to the neutron beam. Simultaneous neutron/ X-ray experiments allows for effective studies of irreversible processes and sensitive samples.

Typical Applications

A (polarised) neutron reflectometry alone and in combination with X-ray reflectometry provides information about spatial distribution of chemical elements and isotopes and magnetic moment. A selected list of examples:

  • Interface phenomena in strongly correlated heterostructures
  • Model surfaces for biofunctional studies
  • Physics and chemistry of liquid/solid and gas/solid interfaces
  • New materials for spintronic, quantum and neuromorphic computing
  • Influence of reduced dimensionality on magnetic properties
  • Soft thin films
  • Material science of thin films and heterostructures
Sample Environment
  • Closed cycle cryostat (down to 3.5 K) with low background sapphire windows
  • 3He cryostat (down to 0.5 K), bottom loaded with large sample space
  • Electromagnet (up to 3.5 T) with versatile field direction in x, y and z
  • In-situ X-ray reflectometer
  • Gas tight chamber with controllable atmosphere (H2, H2O, Ar, N2, etc.) and temperature (up to 600 K)
  • Humidity control system. Humidity 0 – 100 % (H2O or D2O), temperature 20°C < T < 50°C.
  • High voltage sample stick (up to 10 kV).
  • In-situ transport measurement
  • γ-detector for surface prompt-gamma analysis
Technical Data
Monochromator
  • Type: 7 × 5 HOPG crystals, horizontal focussing
  • Wavelengths: 2.9 – 5.5 Å
  • Wavelength resolution: 1…2 %
  • Distance to sample: 2500 mm
Collimation
  • Vertical
    • Slit sizes: 0.2 – 6 mm
    • Divergence: 0.05 – 1.4 mrad
  • Horizontal
    • Slit: 0.2 – 100 mm
Polarisation
  • Polarisation: > 99.9 %
  • Analyser: > 99.0 %
  • Flipper efficiency: > 99.99 %
Detector
  • 2 pencil detectors: 3He
  • 2D area detector: 3He wire chamber
  • Active area: 200 × 200 mm2
  • Lateral resolution: 3 mm
  • Distance to sample: 2465 mm
Estimated flux at sample (λ = 2.9 Å , 0.3 mrad beam divergence)
  • Non-polarised: 3 · 105 n cm-2 s-1
  • Polarised: 1 · 105 n cm-2 s-1
Dynamical- and Q-Range:
  • Specular reflectivity: 1 : 1 ·10-6 (@ 5 × 5 mm² sample and full polarization)
  • Limits of Q-components (for λ = 2.9 Å)
    • Qz: 0.0075 – 0.75 Å-1
    • Qx: 7.5 · 10-5– 7.5 ·10-3 Å-1
    • Qy: 0.03 – 2.3 Å-1
X-rays
  • Source: Cu-Kα fixed anode (1.54 Å)
  • Monochromator: Göbel Mirror & Double Ge-Crystal
  • Detector: 1-dimensional DECTRIS

Instrument Scientists

Dr. Yury Khaydukov
Phone: +49 (0)89 289-14769
E-Mail: Y.Khaydukov@fkf.mpg.de

Dr. Thomas Keller
Phone: +49 (0)89 289-12164
E-Mail: T.Keller@fkf.mpg.de

NREX
Phone: +49 (0)89 289-14878

Operated by

MPG

Publications

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

impulse.mlz-garching.de

Citation of the instrument

Max-Planck-Institut für Festkörperforschung and Heinz Maier-Leibnitz Zentrum. (2015). NREX: Neutron reflectometer with X-ray option. Journal of large-scale research facilities, 1, A38. http://dx.doi.org/10.17815/jlsrf-1-30

For citation please always include the DOI.

Gallery

NREX
NREX
© W. Schürmann, TUM
Scattering-Map
Scattering-Map

Scattering-map of spin-up neutrons from the [Fe(10 nm)/Si(10 nm)]x50-multilayer measured in magnetic field H = 1 kGs applied in-plane of the structure (scheme of the experiment on the up-right inset). Left-bottom inset: specular reflectivities for different spin channels

Left: Reflectivity curves from the periodic heterostructure [La0.7Sr0.3MnO3(2 nm)/SrRuO3 (8 nm)]x15 measured at T = 3 K (sample surface area 5 × 10 mm2). Right: Model of the spin configuration explaining experimental data. Taken from J.-H. Kim et al. Phys. Rev. B 86, 180402® (2012)

MLZ is a cooperation between:

Technische Universität München> Technische Universität MünchenHelmholtz-Zentrum Hereon> Helmholtz-Zentrum Hereon
Forschungszentrum Jülich> Forschungszentrum Jülich

MLZ is a member of:

LENS> LENSERF-AISBL> ERF-AISBL

MLZ on social media: