Unique 2D–3D Structure Transformations in Trichalcogenide CrSiTe3 under High Pressure

Using external stimulants to tune the structural and physical properties of chalcogenides has become a hot research topic due to the potential applications in high-temperature superconductors and geological physics. The typical 2D-like trichalcogenide CrSiTe3 has special atomic, electronic, and magnetic features, expected to exhibit interesting structure and property transformations under pressure. Using the synchrotron X-ray diffraction and first-principles calculations, we discover an interesting pressure-induced 2D-3D polymorphic transformation in CrSiTe3 at 15 GPa followed by an amorphization process, which may originate from the disordering of the chemical bonding rearrangement in "Si2Te6" clusters. The pressure-induced metallization and spin-reorientation transition of CrSiTe3 in the low-pressure range are predicted through simulations. Our results shed light on the complicated bonding mechanism that leads to special structural transformations in CrSiTe3 and would encourage further investigations on trichalcogenides as well as other 2D-like materials under extreme conditions.