High-Field Diffractometer@UE46

High-Field Diffractometer /UE46

The High-Field Diffractometer@UE46_PGM-1 (Instrument for Dichroic Soft X-ray Absorption and Scattering Experiments in High Magnetic Fields) is situated at the elliptical undulator UE46_PGM-1, which provides soft x-rays with tunable polarization (linear, circular) in the energy range between 120 eV and 2000 eV. The instrument is dedicated to both soft-x-ray absorption (XAS) and resonant soft x-ray scattering (RSXS) in magnetic fields up to 7 Tesla and temperatures down to 4 K. This combination of high magnetic fields and low temperatures renders the setup ideal for studying weakly coupled magnetic systems like diluted magnets or single molecular magnets. The unique feature of this instrument is an in-vacuum superconducting coil that can be rotated independently from the sample. It is therefore perfectly suited for XMCD and XMLD experiments in various geometries. The absorption signal is typically measured in the TEY-mode via the sample drain current. Employing continuous mode, a pair of energy-dependent absorption scans with opposite light helicities can be recorded with very high quality within less than 10 minutes. Depending on the sample, noise ratios as low as 10-4 can be achieved. A rotatable photon detector enables to perform dichroism experiments using specular reflectivity, which is often more sensitive to tiny magnetizations at interfaces and less surface sensitive than TEY-mode experiments. The same detector permits RSXS experiments at relevant scattering geometries to study the evolution of electronic ordering phenomena, like charge and orbital ordering in high magnetic fields, being at the heart of many of today’s most fascinating macroscopic phenomena in complex oxides. Samples are transferred in a fast and reliable way from outside vacuum to a sample holder directly attached to a LHe-flow cryostat that provides the base temperatures of 4 K. The UE46_PGM-1 beamline also hosts the XUV Diffractometer, an instrument dedicated to high performance RSXS studies. It is possible to switch between both instruments within the same beam time.

Selected Applications:
  • Diffraction from complex electronic superstructures (magnetic, charge and orbital order)
  • Magnetization states of single molecular magnets
  • Element-specific magnetic hysteresis loops (switching behavior in heterostructures or alloys, exchange bias)
  • Electronic ground states in crystals
High-Field and XUV Diffractometer at the UE46 PGM-1 beamline.

High-Field and XUV Diffractometer at the UE46 PGM-1 beamline.


Methods

Elastic Scattering, Magnetic Scattering, REXS, XMCD, XMLD, Reflectometry

Remote access

depends on experiment - please discuss with Instrument Scientist

Instrument data
Phone (~49 30 8062-) 14717
Beam availability 12h/d
Source UE46_PGM-1 (elliptical undulator)
Monochromator PGM
Energy range (at experiment) 120 - 2000 eV
Energy resolution 10 000
Flux 1012
Polarisation
  • linear any angle (with restrictions)
  • circular
Focus size (hor. x vert.)
  • focussed beam:
    typically 100 µm x 50 µm
    ultimate 40 µm x 10 µm
  • collimated beam:
    ≤ 1.7 mm x 1.5 mm (depending on apertures)
Temperature range 4 - 350 K
Pressure range < 10-10 mbar
Detector AXUV100 type photodiode
Manipulators x/y/z
Sample holder compatibility
  • Scattering Geometry: horizontal
  • Sample rotation: limited, depending on orientation of the magnet
  • Software: SPEC
  • Native sample holders
  • Omicron sample plates
Additional equipment
  • Magnetic Field: 7 Tesla
  • Magnetic Field Geometry: horizontal, rotatable (90 deg.) with respect to sample
  • Pulsed magnetic fields up to 30 Tesla becoming available for selected experiments, please contact Instrument Scientists
Additional information Further details: beamline UE46_PGM-1
Magnet angles and slits to estimate possible x-ray scattering geometries (courtesy A. Frano).

Magnet angles and slits to estimate possible x-ray scattering geometries (courtesy A. Frano).


Techniques employed at UE46_PGM-1 include polarization-dependent x-ray absorption and resonant soft x-ray scattering experiments, covering a wide range of materials and scientific problems. Continuous-mode scanning is implemented at the beamline, a pair of energy-dependent x-ray absorption scans with opposite light helicities can be recorded with very high quality within less than 10 minutes. Depending on the sample, noise ratios as low as 10-4 can be achieved.