$\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$, an emergent van der Waals (vdW) magnetic semiconductor, has sparked tremendous interest because of its excellent physicochemical characteristics and potential applications in spintronic and optoelectrical devices. In the present work, the high-temperature and high-pressure magnetic, structural, and electrical transport properties of $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ were comprehensively investigated using an externally heated diamond-anvil cell (DAC) coupled with in situ Raman spectroscopy and electrical conductivity measurements. $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ endured a structural transition at 4.4 GPa, followed by the metallization at 25.4 GPa under nonhydrostatic condition. Under hydrostatic condition, the metallization of the sample was delayed by ∼2.0 GPa due to the influence of deviatoric stress. Upon depressurization, the structural transition of $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ was unveiled to be reversible with the existence of residual strain under different hydrostatic environments. The Ohmic response of $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ under high pressure was disclosed by the linear correlations between sinusoidal voltage and electrical current (α≈1.0). At a specific pressure of 0.4 GPa, the temperature of magnetic transition in $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ was determined as 373 K. In conclusion, our obtained high-temperature and high-pressure results on $\mathrm{N}{\mathrm{b}}_3\mathrm{B}{\mathrm{r}}_8$ can lay the foundation for advancing the exploration on the physicochemical properties of other metallic halides $\mathrm{N}{\mathrm{b}}_3{X}_8$ ($X=\mathrm{Cl}$ and I) under extreme conditions, contributing to their prospective developments in spintronic and optoelectronic devices.

Close

PrevNext

View figure in article

• Magnetic phase transitions
• Magnetism
• Pressure effects
• Structural properties
• Kagome metal
• Magnetic semiconductors
• van der Waals systems
• Pressure techniques
• Raman spectroscopy
• Resistivity measurements