MAXYMUS

MAXYMUS

(MAgnetic X-raY Microscope with UHV Spectroscopy) end station has been installed in cooperation of BESSY II and MAX-PLANCK-SOCIETY in 2009, in charge of Prof. Dr. Gisela Schütz, head of the department "Modern Magnetic Systems", Director and Scientific Member at Max-Planck-Institut for Intelligent Systems in Stuttgart.

MAXYMUS is a scanning x-ray microscope (STXM), where a focused x-ray-beam-spot illuminates the sample surface pointwise. Light passing through the sample gets registrated during dwell time by x-ray sensitive detectors (photomultiplier, avalanche diode or x-ray sensitive CCD camera).

In combination with spectroscopic methods, the microscope provides element specific information on the density distribution of local chemical, electronic and magnetic structure of solids.

MAXYMUS operated, serviced and enhanced continuouesly by MPI-IS Stuttgart Dep. Schütz since 2011, settled permanently at branch pgm2 of the undulator-beamline UE46 at BESSY II (C12.1), is open for proposals.

MAXYMUS Microskope in UHV Configuration with Sample Transfer Chamber

MAXYMUS Microskope in UHV Configuration with Sample Transfer Chamber

MAXYMUS internals as seen through open hatch

MAXYMUS internals as seen through open hatch

List of publications
Station data
Monochromator
  • eff. Energy from 150 eV upto 1900 eV
  • One high flux, 600 l/mm blazed (0.7° angle) and a high resolution 1200 l/mm grating
  • variation of the deflection angle by plane mirror
Experiment in vacuum yes
Temperature range
  • Typically room temperature
  • 80K to RT using cryostat sample holder
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 upcomming
Manipulators
time Resolution
  • Multi Bunch: 35 psec
  • Low Alpha: 10 psec
atmosphere
  • Ultra High Vacuum (< 10-8 mbar)
  • Helium for sample cooling
Sample handling
  • UHV sample preparation chamber (sample magazine, Ar-sputtergun, ebeam baking, airfree transfer)

Methods

Time-resolved studies, NEXAFS, XMCD, EXAFS, XRF, Photoelectron EM, X-ray Microscopy, XPS

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)