Pressure-driven structural phase transitions and metallization in the two-dimensional ferromagnetic semiconductor CrBr₃

Abstract

A systematic and detailed investigation on the high-pressure structural, electrical transport and magnetic properties was conducted for CrBr3.

Pressure-driven structural and electronic transitions in a quasimolecular layered compound of antimony triiodide

“…Importantly, both the high electrical conductivity value of 0.041 S cm −1 at 33.1 GPa and the weak dependence of the electrical conductivity on pressure at a feeble rate of 0.078 S cm −1 GPa −1 are the representative signatures of metallization in SbI 3 . 12–16,22 Upon decompression, two prominent inflection points in electrical conductivity at 28.9 GPa and 3.0 GPa were correlated to the reversal of phase transitions, and the unrecoverable electrical conductivity magnitude further validated the irreversibility of the phase transition. Noteworthily, the recovered sample possesses superior electrical transport properties compared to the starting sample with a substantial improvement in the electrical conductivity by six orders of magnitude after pressure treatment, which may inspire the development of high-performance optoelectronic devices in SbI 3 .…”

“…According to the solid-state physics theory, a semiconductor has a positive temperature dependence relationship with the electrical conductivity, while a negative temperature dependence relationship with the electrical conductivity is observed for a metal. 12–16,22,32–34 It can be seen from Fig. 5 and 6a that SbI 3 underwent a semiconductor-to-metal transformation as the pressure was enhanced above 33.5 GPa, which was demonstrated by the conversion from positive to negative in the temperature dependence of the electrical conductivity relationship.…”

“…Therefore, the noticeable pressure delay of ∼5.0 GPa for the emergence of the third phase transition in SbI 3 under hydrostatic condition is presumably caused by the smaller deviatoric stress, resembling other 2D materials. 12–16,22…”

“…were considered as a better choice due to their stable physicochemical properties and high hydrostaticity, which has been reported to prominently influence the structural properties of 2D materials under high pressure. 12–16,19–22 As for SbI 3 , the related research on the high-pressure structural behaviors under both non-hydrostatic and hydrostatic conditions is still lacking.…”

Pressure-Driven Structural and Electronic Transitions in a Two-Dimensional Janus WSSe Crystal

“…Nevertheless, the well-resolved lattice fringes and the well-defined diffraction spots for the decompressed sample under hydrostatic conditions relative to those under nonhydrostatic conditions can be reasonably interpreted by the presence of PM, resembling other representative two-dimensional (2D) layered compounds (e.g., CrCl 3 , CrBr 3 , HfS 2 , etc.). 26,41,54 3.5. First-Principles Theoretical Calculation Results.…”