Pressure-modulated lattice structural evolution in TiS₂

Area of Science:

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

Background:

• Titanium disulfide (TiS2) is a promising material for energy storage and thermoelectric applications.
• Controlled synthesis of high-quality TiS2 remains a significant challenge.
• Understanding its phase transitions under pressure is crucial for exploring novel electronic properties.

Purpose of the Study:

• To present a straightforward, one-step chemical vapor transport (CVT) synthesis of TiS2.
• To investigate the pressure-induced phase transitions of TiS2.
• To explore the electronic topological states and physical phenomena in TiS2 under high pressure.

Main Methods:

• One-step chemical vapor transport (CVT) synthesis.
• High-pressure (HP) Raman spectroscopy.
• First-principles calculations.

Main Results:

• A facile and widely accessible one-step CVT method for TiS2 synthesis was established.
• TiS2 undergoes phase transitions at 16.0 GPa (Phase I to Phase II, C2/m) and 32.4 GPa (Phase II to Phase III, P6̄2m).
• High-pressure phases of TiS2 were identified within the Weyl semi-metallic phase.

Conclusions:

• The study provides a simplified synthesis route for TiS2.
• The discovered high-pressure phases and transitions offer new insights into the electronic topological states of TiS2.
• This research advances the development of novel electronic devices and fundamental understanding of material properties.