VLEED spin polarization detector:
The FOCUS FERRUM
To overcome the restrictions of conventional spin detectors (Mott, SPLEED) low energy electron scattering at a Fe(100)-p(1×1)O surface was first proposed by Bertacco and Ciccacci [Phys. Rev. B 59, 4207 (1999)] as a system for highly efficient spin detection.
We developed a new instrument based on that scheme. The iron is prepared in-situ on a W(100) crystal without the need for separate sample preparation and exchange when using a MgO substrate.
Our working point at 6.3 eV scattering energy is consistent with the above paper by Bertacco and Ciccacci. With a Sherman-function of 29% and a reflectivity of more than 10% the figure of merit (FOM) is more than one magnitude higher compared to conventional detectors.
And: The FOM shows no degradation over weeks in UHV!
The FERRUM without its Mu-metal vacuum housing, without oxygen doser and iron evaporator.
Important figures of the FERRUM:
Scattering energy: 6.3±0.1 eV
Sherman function: S=0.29±0.01
Reflectivity (I/I0): R>10.6%
Figure of merit : FoM=8.8×10-3
Lifetime (without preparation): Several weeks
The detector can be fitted to most of common energy analyzers like hemispherical or cylinder sector ones.
Please find for example a recent application note about its combination
with the SPECS PHOIBOS 150.
As the most versatile and compact combination of the detector with an energy analyzer we offer the EasySPIN.