GD-DOPED EUO - TEMPERATURE DEPENDENCE OF THE 4F-PHOTOELECTRON SPIN POLARIZATION

The spin polarization of the 4f electrons photoemitted from ferromagnetic EuO+x-at.% Gd (x=0.1,2.0,4.3) has been measured for temperatures T20 K. During the photoemission process depolarization of the excited electrons takes place. At low temperatures, the depolarization is nearly constant. It is attributed to spin-flip scattering of the photoelectrons with not ordered Eu2+ moments existing at irreqularities of the surface. On approaching Tc, the depolarization increases. this is expected because near Tc the magnetization of the ideal, i.e., atomically smooth part of the surface deviates significantly from the one of the bulk, thereby giving rise to additional spin-reversal scattering. © 1979 The American Physical Society.