Aberration corrected spin polarized low energy electron microscope.

Spin Polarized Low Energy Electron Microscopy (SPLEEM) is a powerful tool to reveal the magnetic structure of ferromagnetic surfaces on the atomic depth scale level[1-3]. With aberration corrected LEEM and a high brightness spin polarized electron gun, high spatial resolution will provide more details for ultra-thin ferromagnetic film studies. This study reports the first realization of aberration corrected SPLEEM (AC-SPLEEM). The performance of the setup was tested on ferromagnetic Fe nanoscale islands on a W(110) single crystal, with spatial resolution of 3.3 nm in spin asymmetry images.

Design and commissioning of an aberration-corrected ultrafast spin-polarized low energy electron microscope with multiple electron sources.

We describe the design and commissioning of a novel aberration-corrected low energy electron microscope (AC-LEEM). A third magnetic prism array (MPA) is added to the standard AC-LEEM with two prism arrays, allowing the incorporation of an ultrafast spin-polarized electron source alongside the standard cold field emission electron source, without degrading spatial resolution. The high degree of symmetries of the AC-LEEM are utilized while we design the electron optics of the ultrafast spin-polarized electron source, so as to minimize the deleterious effect of time broadening, while maintaining full control of electron spin. A spatial resolution of 2nm and temporal resolution of 10ps (ps) are expected in the future time resolved aberration-corrected spin-polarized LEEM (TR-AC-SPLEEM). The commissioning of the three-prism AC-LEEM has been successfully finished with the cold field emission source, with a spatial resolution below 2nm.