DIRECT CALCULATION OF VALENCE-BAND EMISSION - SPIN POLARIZATION OF AUGER ELECTRONS FROM A POTASSIUM(110) SURFACE

We report calculations on spin-polarized Auger electron emission from the valence band of a potassium (110) film. In treating this process w e use an N-electron scheme that is based on a generalized version of d ensity-functional theory. The transition rate is determined by explici tly evaluating the transition matrix elements that contain the four st ates involved. The core and valence states are obtained from a self-co nsistent full-potential Linearized augmented plane wave calculation on a K(110) multilayer. In the experiments that the present calculations refer to, the particular oriented core-hole state is created by photo excitation using circularly polarized light. The observed energy spect rum and the angular dependence of the spin polarization of the emitted Auger electrons can be simply related to the character of the spinor- hole state. We compare our results for normal incidence of the light t o the pertinent experiments on the Auger spin polarization referenced to the spin of the incoming photons. The results are in fair agreement with each other.