Cr-based van der Waals compounds as a platform to reach two dimensional ferromagnets. A comparative study between CrBr₃ and Cr₂Ge₂Te₆

Two dimensional ferromagnets (2DFM) have been recently synthesized for the first time causing a great excitement in the community due to their potential applications. Cr-based van der Waals ferromagnets have been identified to be the parent platform to build many of these 2DFM. In this talk, we present a pressure-dependent comparative study, both theoretical and experimental, between CrBr₃ and Cr₂Ge₂Te₆. We analyze the relationship between their electronic structure and the evolution of their magnetic properties with pressure. While CrBr₃ is found to be a robust Mott-Hubbard-like insulator in which the magnetic exchange constants evolve monotonically, Cr₂Ge₂Te₆ has a charge transfer character which makes the in-plane exchange constant to reach a constant value with pressure. This dissimilar microscopic behavior leads to a different evolution of the transition temperature for each compound. Evidence of a possible phase transition around 7 GPa is also provided for Cr₂Ge₂Te₆ [1].

[1] J . Mater . Chem . C , 2020, 8, 13582.