Vectorial multichannel-spin-polarimetry and the analysis of spin-transport in metal-organic interfaces
Loading...
Files
Date issued
Authors
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Reuse License
Abstract
Photoemission spectroscopy has become the key technique for the investigation of electronic
properties of promising materials such as Heusler compounds, Weyl systems, materials
exhibiting a strong Rashba effect, topological insulators or hybrid metal-organic
interfaces. During the last decade photoemission spectroscopy without spin resolution
enjoyed a considerable increase in performance due to parallel image detection while the
spin polarization analysis of a given electron beam remained time consuming. Since potential
candidates for spintronic applications such as metal-organic interfaces tend to degrade
within a short period, a massive reduction of spin-resolved data acquisition time is crucial.
A newly developed high-performance imaging spin filter system based on a large Ir(001)
scattering crystal tackles this issue by enhancing the measurement efficiency. An increase
of the effective figure of merit by a factor of over 103 in contrast to standard single-channel
detectors is presented together with a detailed characterization of the experimental setup.
Furthermore, the spectrometer resolution, spin filter preparation and lifetime are reviewed.
An energy and angular resolution of 27 meV and 0.23◦ has been determined for an energy
and angular acceptance of 1.5 eV and ±10◦. The spin filter efficiency is analyzed by
mapping a broad range of scattering energy and azimuthal angle. A Sherman function
of up to 0.44 has been measured under ideal conditions. If the scattering plane coincides
with a mirror plane of the crystal, the spin filter is only sensitive to the component of
the spin vector perpendicular to the scattering plane. A scattering plane that does not
coincide with a crystal mirror plane yields a high sensitivity to spin vector components
that are parallel to the scattering plane. A spin rotator element enables the independent
determination of the two in-plane components of the spin vector. By combining three or
six scattering conditions a vectorial spin analysis becomes possible for both, magnetic and
non-magnetic samples.
Spin-resolved spectra of Fe/W(110) and H2TPP films of different thickness on Fe/W(110)
are measured with the efficient multichannel spin-resolving photoemission spectrometer
and with the ESPRESSO spectrometer at the Hiroshima Synchrotron Radiation Center.
The experimental results allow for a determination of the spin diffusion length within the
molecular film.