MAXYMUS

MAgnetic X-raY Microscope with UHV Spectroscopy

MAXYMUS is a scanning transmission X-ray microscope (STXM) applying soft x-rays with tunable polarization (linear, circular) in the energy range between 200 eV and 1900 eV. MAXYMUS operates by focusing a coherent x-ray beam to a nanoscale spot which is scanned across the sample. To probe the local absorption, x-rays passing through the sample are measured for each point by a variety of available x-ray detectors including photomultiplier, avalanche diode or in-vacuum CCD camera. This allows to do element specific, chemically and magnetically sensitive imaging with resolutions <20 nm.

Selected Applications:
  • X-ray microscopy
  • Time-resolved magnetic imaging
  • Nanospectroscopy for energy research
  • NEXAFS imaging for environmental science
MAXYMUS Microscope in UHV Configuration with Sample Transfer Chamber

MAXYMUS Microscope in UHV Configuration with Sample Transfer Chamber


Methods

Ptychography, X-ray Microscopy, NEXAFS, XMCD, XMLD, Time-resolved absorption

Remote access

not possible

Beamline data
Energy range 200 - 1900 eV
Energy resolution > 5 000
Flux 200 eV - 1000 eV: ~ 1013 Ph/sec/100mA
Polarisation Horizontal, Vertical, Circular positive, Circular negative
Focus size (hor. x vert.)
  • at exit slit: ~ H 45 µm x V 15µm
  • at zoneplate: ~ H 2 mm x V 1mm
Phone +49 30 8062 14762
More details UE46_MAXYMUS
Station data
Temperature range
  • Typically room temperature
  • 30 - 350 K using cryostat sample holder
Pressure range
  • < 10-8 mbar in UHV mode
  • mbar Helium for passive sample cooling
Detector
  • Photomultiplier E <600 eV
  • Avalanche Photodiode (APD) for fast (<2ns) single photon detection and high count rates (> 108 photons/s)
  • Sample Current (TEY) for non-transparent samples
  • Fast in Vacuum X-Ray CCD
Manipulators
  • Interferometer stabilized high fidelity piezo scanning stage
  • Tiltable sample holder for in-plane XMCD imaging
Sample holder compatibility
  • Standard ALS/PSI Style STXM sample holders
  • Custom HF sample PCBs for >30 GHz bandwidth
  • Local in-vacuum sample storage
Additional equipment
  • He/N2 cryostats
  • Magnetic fields up to 250 mT
  • Picosecond laser system (in collaboration with MBI)
  • High-frequency electronics for sample excitation and signal detection (> 30 GHz)
  • Supporting optical microscopy and wire bonder
Time resolution
  • Multi Bunch: 100 psec
  • Low Alpha: 10 psec
MAXYMUS internals as seen through open hatch

MAXYMUS internals as seen through open hatch


(MAgnetic X-raY Microscope with UHV Spectroscopy) is a scanning transmission x-ray microscope (STXM) and a fixed endstation of the UE46-PGM2 undulator beamline. MAXYMUS has been installed in cooperation of BESSY II and MAX-PLANCK-SOCIETY in 2009, with Prof. Dr. Gisela Schütz, head of the department "Modern Magnetic Systems", Director and Scientific Member at Max-Planck-Institut for Intelligent Systems in Stuttgart, in charge.

MAXYMUS operates by focusing a coherent x-ray beam to nanometer-sized spots which are scanned across sample. To probe the local x-ray absorption, light passing through the sample is measured for each point by a variety of available x-ray detectors including photomultiplier, avalanche diode or in-vacuum CCD camera.

This allows to use x-ray spectroscopic techniques as contrast mechanism, making it possible to do element specific, chemically and magnetically sensitive imaging with resolutions below 20 nm.

MAXYMUS has been in continuously improved since entering user operation since 2011 and is open for proposals.

MAXYMUS endstation allows users to utilize XMCD and NEXAFS contrast mechanisms both for imaging and for nano-spectroscopy of samples, in the energy range between 150 and 1900 eV and on sub 30nm length scales.

Samples can be transparent (the classical mode) as well as bulk, with imaging being done by sample current measurement (TEY - total electron yield).

Scan options include NEXAFS point and line profiles as well as automated NEXAFS stacks (i.e. a full image is taken for each energy point, allowing extraction of spectra for arbitrary areas of interest in post processing).

In particular for XMCD, angled illumination of the sample
is possible for imaging of in-plane magnetization.

The endstation includes a fully featured RF-pump-and-probe setup for time resolved imaging of magneto dynamics.
Giving the user full control and wide flexibility in terms of repetition rates and resolutions [1,3], time resolutions <100ps and spatial resolutions <30nm are operational.

For low photon energies, an efficient photomultiplier detector allows imaging down to the sulfur k-edge. Together with the high flux beamline with reduced carbon absorption, this allows fast aquisition even in low-flux operation modes of BESSY [2].

 


Publications:
 


[1] Kammerer, M.; Weigand, M.; Curcic, M.; Noske, M.; Sproll, M.; Vansteenkiste, A.; Van Waeyenberge, B. ; Stoll, H.; Woltersdorf, G.; Back, C. H.; Schütz, G.:
Magnetic vortex core reversal by excitation of spin waves
Nature Communications 2 279-284 (2011)

[2] Pöhlker, C.; Wiedemann, K. T.; Sinha, B.; Shiraiwa, M.; Gunthe, S. S.; Smith, M.; Su, H.; Artaxo, P. ; Chen, Q.; Cheng, Y.; Elbert, W.; Gilles, M. K.; Kilcoyne, A. L. D.; Moffet, R. C.; Weigand, M.; Martin, S. T.; Pöschl, U.; Andreae, M. O.:
Biogenic potassium salt particles as seeds for secondary organic aerosal in the amazon.
Science 337 1075-1078 (2012)

[3] Bisig, A.; Stärk, M.; Mawass, M.-A.; Moutafis, C.; Rhensius, J.; Heidler, J.; Büttner, F.; Noske, M. ; Weigand, M.; Eisebitt, S.;
Tyliszczak, T.; Van Wayenberge, B.; Stoll, H.; Schütz, G.; Kläui, M.:
Correlation between spin structure oscillations and domain wall velocities
Nature Communications 4 (2013)