Spin Polarization of the Conduction Bands of Gd(0001)*

Angle- and spin-resolved photoemission was utilized to investigate the 5d bulk bands and the surface state of Gd(0001) in the temperature range of 130 - 350 K. The bulk bands at 1-2 eV below the Fermi energy EF show Stoner-like behavior, while the temperature dependence of the surface state near EF indicates spin-mixing behavior due to fluctuating local 5d moments. The secondary electron spectra of the Gd surfaces both before and after initial oxygen adsorption show a polarization dip at low kinetic energies due to the extra scattering channel for minority electrons via the unoccupied 4ƒ level. The temperature dependences of the surface and bulk magnetization are separated using the spin polarization of the surface state and the bulk exchange splitting.