Abstract
The field-emitted electrons from ferromagnetic thin film coated refractory metallic tips may be highly spin-polarized. Together with the high brightness offered by the electron field emission, it is possible to construct a new kind of spin-polarized electron source that provides both high spin-polarization and high intensity. In this thesis a system of Co thin films on W (111) surface is studied by utilizing a compact retarding-potential Mott detector of high-efficiency to find out the feasibility of such a spin-polarized electron source. Construction and calibration of the experimental instrument is described in detail and measurement results on spin-polarization of electron beams from Co/W( 111) system under different growth condition are presented.