Correlation Effects in van der Waals CrXTe3 Materials (X: Si, Ge) from X-ray Spectroscopy Studies

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The recently discovered CrXTe 3 (X: Si, Ge) layered ferromagnets are under increased attention for the demonstration of low-dimensional ferromagnetism down to the monolayer limit. In the present study, we employ near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and resonant photoelectron spectroscopy (ResPES) at the Cr L 2,3 absorption edge accompanied by DFT calculations to gain insights into the electronic structure and electron correlation effects for these compounds. It is found that the 3 d n –1 final state in the photoemission spectra is located at the top of the valence band, thus assigning CrXTe 3 to the Mott–Hubbard state. Moreover, as revealed in NEXAFS and ResPES, significant hybridization between Cr 3 d and Te 5 p valence band states is found in both compounds, leading to the slightly weaker electron localization in CrGeTe 3 as compared to CrSiTe 3 . Our results bring new insight into the deep understanding of the correlation phenomena in these vdW materials allowing us to draw further ways on the modulation of the correlation effects and magnetic structures in different layered compounds.