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.
To download an actual flyer about FERRUM and EasySPIN please click here.
Please find more detailed informations at
e-J. Surf. Sci. Nanotech. Vol. 9 (2011) 340-343.