Polarized neutron reflectometry study of thin Fe films prepared on V (100)

The magnetic properties of ultrathin Fe (1 0 0) films were investigated by polarized neutron reflectometry (PNR). Fe films with different thicknesses from 1 to 3 nm were prepared by Molecular Beam Epitaxy (MBE) on a V buffer layer, which was deposited on a MgO (1 0 0) single crystal. In order to avoid oxidation the Fe films were covered with V capping layers. During the preparation process the growth of the films was monitored by low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES). Combining the information obtained from PNR with X-ray reflectometry (XRR), the thicknesses of the Fe and V layers were determined precisely. From PNR measurements the absolute value of the magnetization of the films could be determined by fitting the spin-up and spin-down neutron reflectivities separately. The magnetic moments of the Fe films show a perfect linear dependence on the film thickness t(Fe). The fitting line intersects the abscissa at t(Fe)-(0.1 +/- 0.01) nm. This means that the magnetic properties of the two V/Fe interfaces show up as a constant reduction of the magnetic moment equal to an Fe bulk layer of thickness t(Fe) = (0.1 +/- 0.01) nm. (C) 2004 Elsevier B.V. All rights reserved.