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

High-pressure structural, magnetic and electrical transport characteristics of CrBr3 were synthetically investigated using Raman scattering, electrical conductivity, high-resolution transmission electron microscopy (HRTEM) and first-principles theoretical calculations during compression and decompression under different hydrostatic conditions. Upon pressurization, CrBr3 underwent a second-order structural transition at 9.5 GPa, followed by the semiconductor-to-metal and magnetic switching at 25.9 GPa under non-hydrostatic conditions, whereas, an obvious pressure hysteresis of similar to 3.0 GPa was detected in the occurrence of structural transitions and metallization under hydrostatic conditions due to the deviatoric stress. Upon decompression, the structural and electronic transitions of CrBr3 under different hydrostatic conditions were of good reversibility with a considerable pressure sluggishness of similar to 5.0 GPa, which was corroborated well by the microstructural observation with HRTEM. Our systematic high-pressure investigation on CrBr3 not only reveals its underlying application in spintronic, magnetic and electronic devices but also advances the understanding of the physicochemical behaviors for 2D magnetic materials.

Automated summary

In this study, the high-pressure structural, magnetic and electrical transport characteristics of CrBr3 were investigated using various techniques. The results showed that CrBr3 underwent structural, electronic and magnetic transitions under different pressure conditions. The reversibility of these transitions was observed upon decompression. This systematic high-pressure investigation provides insights into the potential applications of CrBr3 in spintronics, magnetic and electronic devices, and improves our understanding of the physicochemical behaviors of 2D magnetic materials.