Observation of spin-polarized-electron tunneling from a ferromagnet into GaAs

Experimental evidence is presented for the tunneling of polarized electrons from the apex of a ferromagnetic Ni tip into GaAs(110). The polarization is found to be negative and of highest magnitude at very low injection energies, which shows that highly polarized minority 3d electrons are preferentially extracted from the Fermi level of the tip. © 1992 The American Physical Society.