DECAY OF THE ELECTRONIC SPIN POLARIZATION OUTSIDE A SURFACE OF A FERROMAGNETIC METAL

It is shown that the spin polarization of the electron cloud in thermal equilibrium with a ferromagnetic surface decays within a few Angstroms from the surface. This explains the vanishing spin polarization found in thermoemission from Ni and Fe by Vaterlaus et al. [Phys. Rev. Letters 65, 3041 (1990)].