Atomic ordering of ferromagnetic alloys, such as Heusler compounds, vastly influences their magnetic properties and overall usability. However, in some cases x-ray diffraction cannot unambiguously determine the correct atomic structure, which hampers further research.
In this paper, we analyze the atomic ordering using spectroscopic ellipsometry-a simple tabletop method that researchers can use in situ during sample deposition. The Co(2)Fe(Ga(0.5)Ge(0.5)) Heusler compound was chosen for the analysis, as the atomic ordering greatly influences its spin-polarizing capabilities.
The ellispometric results are confronted with x-ray diffraction and with the help of ab initio calculations the qualitative changes in the optical response are linked to the changes in atomic ordering.