Observation of high spin polarization of half-metallic ferromagnetic Fe/sub 3/O/sub 4/ and CrO/sub 2/ by spin-resolved photoelectron spectroscopy at room temperature

Summary form only given. The theoretically predicted 100% spin polarization at the Fermi level E/sub F/ of the half-metallic ferromagnets Fe/sub 3/O/sub 4/ and CrO/sub 2/ makes them promising materials for magnetoelectronic devices. According to Julliere´s model the tunnel magnetoresistance (TMR) of ferromagnet/insulator/ferromagnet tunnel junctions is proportional to the spin polarization of the ferromagnetic electrodes. This fact has revived research interest on the half-metallic ferromagnetic materials like Heusler alloys, manganites, Fe/sub 3/O/sub 4/ and CrO/sub 2/. We present the experimental measurements of the spin polarization of magnetite and chromium dioxide epitaxial films by means of spin- and angle-resolved photoemission spectroscopy at room temperature.