Structural, magnetic, electronic, and spin transport properties of epitaxial Fe3Si/GaAs(001) -: art. no. 094401

We report experimental results on the structural, magnetic, electronic, and spin transport properties of a 21 nm Fe3Si/GaAs(001) heterostructure epitaxially grown by coevaporation. High-resolution x-ray diffraction shows an almost stoichiometric film, which is lattice matched in-plane to the GaAs substrate and therefore slightly tetragonal distorted. Polarized neutron reflectometry measurements yield a magnetic moment of (1.107 +/- 0.014)mu(B) per atom at room temperature (RT), while superconducting quantum interference device magnetometry yields a magnetic moment of (0.9 +/- 0-0)mu(B) per atom at RT, both close to the bulk value. Magneto-optic Kerr effect measurements show that this system has in-plane cubic anisotropy with easy axes along the 100) directions and a cubic anisotropy constant K-1 =(3.1 +/- 0.6) X 10(4) erg/cm(3) at RT. A resistivity of (4.1 +/- 0.4) X 10(-7) Omega in in the Fe3Si film was measured, which is close to the bulk value. Optical spin orientation in the GaAs was used for spin transport measurements and spin detection is demonstrated at RT for this system. Point contact Andreev reflection spectroscopy was used to determine the spin polarization of the transport current, yielding P=(45 +/- 5)%.