Noncollinear Magnetization Structure at the Thickness-Driven Spin-Reorientation Transition in Epitaxial Fe Films on W(110)

An in-plane spin-reorientation transition occurring during the growth of epitaxial Fe films on W(110) was studied in situ by using the nuclear resonant scattering of synchrotron radiation. The spin-reorientation transition originates at the $\mathrm{Fe}/\mathrm{W}(110)$ interface and proceeds via a noncollinear spin structure resembling a planar domain wall that propagates towards the surface with increasing film thickness.

Figure 1

The time spectra accumulated during continuous Fe evaporation labeled with the corresponding Fe thicknesses are shown. The top and bottom spectra reflect according to the theoretical fits (continuous line) homogenous magnetization states with the easy axis along $[1\overline{1}0]$ and [001], respectively.

Figure 2

The best fits to the time spectrum measured for $d=53.2\AA$, obtained within the domain (black line) and coherent rotation (orange [gray] line) models.

Figure 3

The magnetization structure during the thickness-induced SRT for the $\mathrm{Fe}/\mathrm{W}(110)$ system, as derived from the NRS measurements using a five sublayer model. The sublayer magnetization vectors are labeled as ${\overrightarrow{M}}_{1–5}$.