Anisotropic x-ray magnetic linear dichroism at the FeL2,3edges inFe3O4

Abstract

X-ray magnetic linear dichroism at the Fe ${L}_{2,3}$ edges of the ferrimagnet ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ was found to exhibit a strong dependence on the relative orientation of external magnetic field, x-ray polarization, and crystalline axes. Spectral shape and magnitude of the effect were determined for ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}(011)$ and ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}(001)$ thin films, varying the in-plane orientation of field and polarization. All dichroism spectra can be described as a linear combination of two fundamental spectra which in turn gives a good agreement with calculated spectra, using atomic multiplet theory. The angular dependence of the magnetic dichroism reflects the cubic crystal field symmetry. It can be used to estimate the crystal field splitting and allows the determination of the spin quantization axis.