Formation of an inversion-asymmetric Janus crystal structure in Fe3GeTe-S(-Se) by exposure to H2S Fe3GeTe2

The proposal aims at evidencing the formation of an inversion-asymmetric Janus crystal structure in Fe3GeTe-S(-Se). Precisely, we target the first realization of a ferromagnetic Janus 2D material, whose novel electronic/magnetic properties are expected to impact the field of spintronics. As shown in our previous studies of SPtSe [1], grazing incidence X-ray diffraction (GIXD) is well suited to monitor in situ the formation of a Janus TMD, and to determine its atomic structure quantitatively. Here, GIXD will allow monitoring the substitution of the top Te layer of a Fe3GeTe2 (FGT) single layer by S and Se, thanks to exposure to atomic fluxes of the corresponding elements.