Defining Laser-Induced Phase Transition and Thermal Response of VO₂ by Raman Spectroscopy: A Comparative Study of...

Area of Science:

• Materials Science
• Solid-State Physics
• Nanotechnology

Background:

• Vanadium dioxide (VO2) exhibits a metal-insulator transition (MIT) with structural changes, making it sensitive to thermal excitation.
• Understanding laser-induced effects on VO2 is crucial for applications leveraging its thermochromic properties.

Purpose of the Study:

• To investigate the impact of Raman laser irradiation on the phase stability and oxidation of VO2 materials fabricated using different methods.
• To establish a correlation between fabrication technique, microstructure, and laser-induced phase behavior in VO2.

Main Methods:

• Characterization using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and UV-Vis-IR spectroscopy.
• Temperature-dependent measurements to assess thermochromic transition behavior.
• Raman spectroscopy with controlled laser excitation to probe localized thermal response and phase stability.

Main Results:

• VO2 powder (prepared by Rapid Thermal Annealing) rapidly oxidized under laser irradiation.
• VO2/PVP composite thin film showed delayed oxidation, requiring higher laser power.
• Sol-gel and Reactive Biased Target Ion Beam Deposition (RBTIBD) thin films exhibited reversible laser-induced phase transitions without oxidation.

Conclusions:

• The fabrication method significantly dictates the laser-induced phase stability and oxidation behavior of VO2 materials.
• Microstructure plays a key role in the material's response to localized thermal excitation.
• Specific VO2 thin films offer promising reversible laser-induced phase transitions for advanced applications.