Enhanced magnetic moments in bcc Fe films

Abstract

We present evidence for enhanced magnetic moments in epitaxial Fe films in proximity with Ag, Au, Cu, and Pd overlayers prepared by molecular-beam epitaxy on singular Ag(001) substrates in a combined study using polarized-neutron reflection (PNR) and ferromagnetic resonance (FMR). Second versions of equivalent samples were investigated in order to test the repeatability of the results, and all PNR measurements were corrected for background and diffuse scattering. Within experimental error, measurements of the absolute value of the magnetic moment per atom made using PNR were found to agree with measurements of the relative magnetization using FMR, and measurements on repeated samples were also found to agree. An average magnetic moment per Fe atom of 2.58±0.09${\mathrm{\mu }}_{\mathit{B}}$ was determined for a Ag/5.5 ML Fe structure, significantly enhanced from the value of ${\mathrm{\mu }}_{\mathrm{Fe}}$=2.33±0.05${\mathrm{\mu }}_{\mathit{B}}$ obtained for a Ag/10.9 ML Fe reference sample. Corresponding values of 2.48±0.08${\mathrm{\mu }}_{\mathit{B}}$ and 2.50±0.10${\mathrm{\mu }}_{\mathit{B}}$ were determined for Cu/5.8 ML Fe and Cu/5.7 ML Fe structures, respectively. Values of the layer averaged moment of 2.66±0.05${\mathrm{\mu }}_{\mathit{B}}$ and 2.6±0.2${\mathrm{\mu }}_{\mathit{B}}$ were determined for Pd/5.6 ML Fe and Pd/5.7 ML Fe structures, respectively, assuming that no induced polarization occurs in the interface Pd layers.