The influence of the interlayer exchange coupling on the magnetism of an Fe(0 0 1) monolayer

We investigated changes in the magnetic properties of a single Fe monolayer on Au(0 0 1) induced by the interlayer exchange coupling (IEC) to FeAu monoatomic superlattices. The grazing incidence nuclear resonant scattering of X-rays (GI-NRS) combined with the 57Fe probe layer concept allowed us to selectively monitor the local structure and magnetism of the Fe(0 0 1) monolayer in a coupled state. The dependence of the monolayer hyperfine parameters on temperature and spacer thickness was determined from the fitted GI-NRS time spectra, collected for the selected thickness of the stepped Au spacer. The influence of the coupling on the hyperfine magnetic field BHF was negligible at temperatures much lower than TC of the uncoupled Fe monolayer (TC = 210 K as checked by MOKE). The analysis of the time-spectra accumulated at 200 K showed a non-monotonous dependence of the average BHF as a function of the spacer thickness, related to IEC oscillations. The maximum influence of IEC on BHF (13 T) was found for the 4 ML Au spacer.