X-ray Absorption Spectroscopic Studies of Pulsed-Laser-Deposited Thin Films of Fe3O4 on Si(111) Substrate

Abstract

We report on the growth and the characterization of magnetite thin films grown on Si(111) substrates by using pulsed laser deposition at different substrate temperatures (T-s = 350, 450 and 550 degrees C) by performing X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) experiments. The O K - and Fe L-3,L-2-edge XAS spectra reveal that the couplings of the O 2p with Fe 3d orbitals highly rely on the growth processes. The XMCD data of well-characterized thin films exhibit characteristic contributions from Fe-A(3+) ions in tetrahedral sites and Fe-B(2+) and Fe-B(3+) ions in octahedral sites and have spectral features similar to those of the Fe3O4 single crystal. The temperature dependence of the XMCD line shape features remain unchanged below and above the Verwey transition. These investigations demonstrate the experimental conditions for controlled growth of Fe3O4 thin films on Si(111) substrates and suggest that the Fe3O4/Si(111) might a promising spintronic materials for future technology.