X-PEEM

The SPEEM instrument consists of a commercial PEEM (ELMITEC) capable of 30 nm spatial resolution for synchrotron light excitation.

An energy analyzer allows the X-PEEM to be used in two modes:

• Imaging analyzer set for detection of secondary photoelectrons generated after irradiation of the sample with the incoming photon beam. In that case the intensity of detected electrons at the screen is proportional to the absorption of the material at the given photon energy. As such it allows to obtain space resolved:
  
  Figure 1:
  
  
  • X-ray absorption spectra by varying the incoming photon energy across the absorption edges of interest and obtaining an image at every energy point.
    
    
  • X-ray Magnetic circular dichroism (XMCD) spectra by varying the incoming photon energy for circular polarized light and obtaining and image at each energy point for a sample magnetized in two opposite directions parallel to the incoming photon beam.
    
    
  • Imaging of ferromagnetic domains by fixing the incoming photon energy and obtaining images for incoming circular polarized photons with left and right helicity. Their difference gives the magnetic contrast
  
  Figure 2:
  
  
  • Imaging of antiferromagnetic domains by using incoming linearly polarized radiation (horizontal and vertical)
    
    
• Imaging analyzer set for detection of core electrons. This is equivalent to X-ray photoemission and allows to obtain information about the core levels. Two Mott polarimeters will allow analysis of all three photoelectron spin components with sub-μm lateral resolution (Figure 3).