L. Bottyan et al., LAYER MAGNETIZATION CANTING IN FE-57 FESI MULTILAYER OBSERVED BY SYNCHROTRON MOSSBAUER REFLECTOMETRY/, Hyperfine interactions, 113(1-4), 1998, pp. 295-301
Synchrotron Mossbauer reflectometry and GEMS results on a [Fe-57(2.55
nm)/FeSi (1.57 nm)](10) multilayer (ML) on a Zerodur substrate are rep
orted. CEMS spectra are satisfactorily fitted by alpha-Fe and an inter
face layer of random alpha-(Fe, Si) alloy of 20% of the 57Fe layer thi
ckness on both sides of the individual Fe layers. Kerr loops show a fu
lly compensated AF magnetic layer structure. Prompt X-ray reflectivity
curves show the structural ML Bragg peak and Kiessig oscillations cor
responding to a bilayer period and total film thickness of 4.12 and 41
.2 nm, respectively. Grazing incidence nuclear resonant Theta-2 Theta
scans and time spectra (E = 14.413 keV, lambda = 0.0860 nm) were recor
ded in different external magnetic fields (0 < B-ext < 0.95 T) perpend
icular to the scattering plane. The lime integral delayed nuclear Thet
a-2 Theta scans reveal the magnetic ML period doubling. With increasin
g transversal external magnetic field, the antiferromagnetic ML Bragg
peak disappears due to Fe layer magnetization canting, the extent of w
hich is calculated from the fit of the time spectra and the Theta-2 Th
eta scans using an optical approach. In a weak external field the Fe l
ayer magnetization directions are neither parallel with nor perpendicu
lar to the external field. We suggest that the interlayer coupling in
[Fe/FeSi](10) varies with the distance from the substrate and the ML c
onsists of two magnetically distinct regions, being of ferromagnetic c
haracter near substrate and antiferromagnetic closer to the surface.