Spin Precession of Electrons upon Reflecting from Ferromagnetic Surfaces

In this work, the reflected part of a spin-polarized electron beam is examined. A spin-polarized electron beam was obtained from a strained GaAs-type source by optically pumping the crystal with circularly polarized light. The beam was incident at a 45deg angle with respect to the surface of the ferromagnetic film. To get the maximal spin motion of the reflected electrons, it is necessary to choose the direction of the incident spin polarization P₀ to be perpendicular to the direction of the magnetization M of the ferromagnetic film. Upon reflection from the film surface, the specular beam passed through a retarding field energy analyzer and was then fed into a Mott detector to measure the spin polarization P.