Spin Polarization due to Low-Energy Electron Diffraction at the W(001) Surface

The spin polarization in low-energy electron diffraction (LEED) from a clean W(001) surface, as well as from a surface exposed to residual gas, has been measured with a newly-constructed compact Mott detector. At a particular electron energy and incident angle, exposure of a clean surface to 0.5 Langmuir of residual gas causes a significant polarization change, from -45% to +31%. This characteristic is not inconsistent with results reported by other workers under different diffraction conditions.