High-efficiency spin polarimetry by very-low-energy electron scattering from Fe(100) for spin-resolved photoemission

We describe concept, design, and performance of a novel spin polarimeter based on spin-dependent specular reflection of electrons from a Fe(100) surface. The Fe surface is prepared as an ultrathin film on Ag(100). By tuning the energy of the electrons to a critical point in the Fe band structure, a large spin asymmetry combined with a large scattering efficiency is achieved. The polarimeter yields a figure of merit up to 10(-2) for the best Fe(100) surfaces. (C) 2002 American Institute of Physics.