Morphology- and Quantum-Size Induced Oscillations of the Electron-Spin Precession in Fe Films on Ag(001)

We report on spin-polarized electron reflection experiments on Fe films on Ag(001). Upon reflecting from the Fe film the electron-spin polarization vector is found to vary in an oscillatory fashion as a function of the Fe thickness. Two different periods are identified. While the long period is related to the occurrence of quantum interference in the Fe layer, the short period of one monolayer is attributed to the periodic variations of the film morphology alternating between filled and incompletely filled atomic layers.