Energy filtered PEEM
The Imaging Energy Filter (IEF) makes the FOCUS PEEM a powerful tool to measure work function maps (with lab sources) as well as element specific maps (with synchrotron, X-ray microspectroscopy) of conductive samples. For time/energy resolved measurements paired with a pulsed excitation source the FOCUS PEEM can be equipped with a Time-of-Flight (TOF) energy filter. All these options can be combined in one instrument for maximum versatility.
The PEEM with IEF and/or TOF combined with the optional angular imaging optics delivers laterally resolved k-space images (momentum microscopy).
IEF PEEM & VUV lab source HIS 14 HD
Imaging of the d-band region of Ag(111), He I excitation (HIS 14 HD, 21.2 eV), E-EF = 15.5 eV, dwell time 5 s, FoV = 20 μm
Right: µ-ARPES of polycrystalline silver. The navigation in the real space is accomplished by use of the iris micro aperture defining the region of interest before switching to k-space imaging.
Because of their different crystallographic orientations the single grains deliver different momentum patterns.
TOF PEEM & Pulsed Laser
The complete k-space of the photoemission from a Au (111) surface (at room temperature), has been excited with a pulsed 210 nm laser (80 MHz rep. rate, 200 x 200 µm2, 17 µW). One can see the surface state and direct sp-sp transitions.
Right: 3D representation of a complete E-kx-ky data cube.
- Real space FoV:
- about 25 µm
- k-space FoV: ±0.575 Å-1
- drift energy: 20 eV
- energy range: 4.3 eV to 5.9 eV (EF)
kx-ky image near to the Fermi energy EF
E–kx image with a sharp parabolic emission horizon.