Octupole Endstation: X-ray Absorption Spectroscopy (XAS) and Magnetic Dichroism (XMLD and XMCD)

 

The sample temperature is variable from 500 K down to ~30 K. 

Vector Magnet
This endstation is a vector electromagnet that can apply a field in any direction with a magnitude of 0.2 T depending on the field direction.  The scattering angular range is a 2-theta of 0-100 deg. and omega is freely variable from 0-360 deg.  The geometry is shown above. 
 
Detection Modes

Electron yield: surface sensitive electron yield via sample current

Fluorescence yeild: using a Vortex energy discriminating detector, of scattering with a photodiode.

NOTE: while we have control of the angular range, the detector reproducibility is not good enough to measure wide angle reflectivity scans as a function of angle.

 
Sample Mounting 
  • For sample mounting we have two options.
    • Flag Style (Cu, SS or Mo): drawing pdf. Samples are introduced via a loadlock.
    • Direct mounting on the cryostat. For this method option, the entire chamber needs to be vented and pump down time ranges from 3 hours for measurements above 150K to 12-24 hours for the pressure to recover enough for low temperature measurements without rapid ice formation.
    •  
  • Samples can be mounted using either Carbon tape or Silver paint/paste. In addition, the cryostat has 4 additional wires available for in-situ device measurements.
  • You can request sample holders to be shipped to your home institution ahead of time; contact beamline staff and provide a FedEx number.
  • IMPORTANT: Getting Ready For Your Experiment