Time-Resolved X-Ray Powder Diffraction Study of Photoinduced Phase Transitions in Ti₃ O₅ Nanoparticles.

Area of Science:

• Materials Science
• Solid-State Physics
• Nanotechnology

Background:

• Titanium sesquioxide (Ti$_{3}$O$_{5}$) nanoparticles are known to exhibit photoinduced phase transitions.
• These light-induced transformations at room temperature suggest potential for technological applications.

Purpose of the Study:

• To directly observe and characterize the photoinduced semiconductor-to-metal phase transition in Ti$_{3}$O$_{5}$ nanoparticles at room temperature.
• To investigate the dynamics and underlying mechanisms of this light-induced phase transformation.

Main Methods:

• Utilized time-resolved X-ray powder diffraction in a pump-probe setup.
• Observed the structural changes from β-Ti$_{3}$O$_{5}$ to λ-Ti$_{3}$O$_{5}$ nanoparticles.

Main Results:

• Directly observed a photoinduced semiconductor-to-metal phase transition in Ti$_{3}$O$_{5}$ nanoparticles at room temperature.
• The structural change was partial and persisted for microseconds after excitation.
• The relaxation back to the ground state followed a single exponential decay with microsecond timescales.
• Estimated an average temperature increase consistent with a thermally driven process.

Conclusions:

• The photoinduced semiconductor-to-metal phase transition in Ti$_{3}$O$_{5}$ nanoparticles is a real phenomenon observable at room temperature.
• The transition dynamics are characterized by microsecond-scale relaxation, suggesting potential for ultrafast optical switching applications.
• The process appears to be thermally driven, providing insights for material design and device engineering.