RIXS exploration of Co doped 2D Fe5GeTe2

Fe5GeTe2 is a new 2d ferromagnet with high Curie temperature. Co doping is predicted to enhance the ferromagnetic transition even more. However it is difficult to establish which among the different Fe species is the main responsible for the stabilization of the ferromagnetic ground state and which of them is replaced by the Co atoms. A study of the dd excitations in the material, which are related to the crystal field interactions, will help us to propose some hypothesis.