High-pressure studies of Bi2S3

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Understanding high-pressure behavior is crucial for materials under extreme conditions.
• Bismuth sulfide (Bi2S3) exhibits unique electronic and structural properties.
• The role of lone-electron pair stereochemical activity in structural transitions is an active research area.

Purpose of the Study:

• To investigate the high-pressure structural and vibrational properties of Bi2S3.
• To determine the pressure-induced structural phase transitions.
• To elucidate the influence of Bi(3+) lone-electron pair activity on structural stability.

Main Methods:

• High-pressure X-ray diffraction (XRD) up to 65 GPa.
• Raman spectroscopy under high pressure.
• First-principles theoretical calculations.

Main Results:

• The ambient Pnma structure of Bi2S3 is stable up to 50 GPa, followed by structural disorder.
• Evidence suggests a second-order isostructural transition around 4-6 GPa, linked to electronic structure changes.
• Bi(3+) lone-electron pair stereochemical activity decreases with pressure but persists well beyond 65 GPa.

Conclusions:

• Bi2S3 undergoes significant structural changes at high pressures, including a potential isostructural transition.
• The persistence of Bi(3+) lone-electron pair activity suppresses transitions to higher crystalline symmetries up to 65 GPa.
• High-pressure studies reveal complex interplay between electronic structure, lone-pair activity, and structural stability in Bi2S3.