Polarized neutron reflectometry study of thin Fe films prepared on V (1?0?0)

Abstract

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 tFe. The fitting line intersects the abscissa at tFe=(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 tFe=(0.1?0.01)?nm.NRC publication: Ye