Imaging spin filter for electrons based on specular reflection from iridium (001).
Ultramicroscopy
; 130: 63-9, 2013 Jul.
Article
in En
| MEDLINE
| ID: mdl-23639852
ABSTRACT
As Stern-Gerlach type spin filters do not work with electrons, spin analysis of electron beams is accomplished by spin-dependent scattering processes based on spin-orbit or exchange interaction. Existing polarimeters are single-channel devices characterized by an inherently low ï¬gure of merit (FoM) of typically 10â»4-10⻳. This single-channel approach is not compatible with parallel imaging microscopes and also not with modern electron spectrometers that acquire a certain energy and angular interval simultaneously. We present a novel type of polarimeter that can transport a full image by making use of k-parallel conservation in low-energy electron diffraction. We studied specular reflection from Ir (001) because this spin-filter crystal provides a high analyzing power combined with a "lifetime" in UHV of a full day. One good working point is centered at 39 eV scattering energy with a broad maximum of 5 eV usable width. A second one at about 10 eV shows a narrower profile but much higher FoM. A relativistic layer-KKR SPLEED calculation shows good agreement with measurements.
Full text:
1
Database:
MEDLINE
Language:
En
Journal:
Ultramicroscopy
Year:
2013
Type:
Article
Affiliation country:
Germany