MAXYMUS

MAXYMUS

(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 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
Temperature range
  • Typically room temperature
  • 80K to RT using cryostat sample holder
Pressure Range
  • < 10-8 mBar in UHV mode
  • mB Helium if cooling is required
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
Sample holder compatibility
Beamline(s)

UE46_MAXYMUS

time Resolution
  • Multi Bunch: 35 psec
  • Low Alpha: 10 psec
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)