Development of a spin polarized low energy electron diffraction system.

Area of Science:

• Surface Science
• Condensed Matter Physics
• Materials Science

Background:

• Low energy electron diffraction (LEED) is a surface-sensitive technique.
• Understanding electron spin interactions at surfaces is crucial for materials science and magnetism.
• Existing techniques may have limitations in measuring specific spin-dependent phenomena.

Purpose of the Study:

• To design and construct a novel spin polarized low energy electron diffraction (SPLEED) system.
• To enable the measurement of spin-orbit and exchange interaction asymmetries.
• To investigate surface structure and magnetism with enhanced precision.

Main Methods:

• Utilized a reflected electron pulse counting mode for SPLEED.
• Employed photoemission from a strained Gallium Arsenide/Gallium Arsenide Phosphide (GaAs/GaAsP) superlattice as the source of spin-polarized electrons.
• Evaluated spin-orbit asymmetry on an Iridium (Ir)(100) single crystal and exchange asymmetry on Iron (Fe) deposited on Ir(100).

Main Results:

• Successfully designed and constructed a functional SPLEED system.
• Demonstrated the capability to measure spin-orbit asymmetry on Ir(100).
• Quantified exchange asymmetry on a 40-monolayer Fe film deposited on Ir(100).

Conclusions:

• The developed SPLEED instrument is effective for analyzing spin-dependent phenomena at surfaces.
• The system provides valuable insights into surface structure and magnetism.
• This technology advances the study of electron spin interactions in materials.