High-temperature and laser-induced phase transitions in α-Ag₃VO₄ nanoparticles: A Raman and DFT study

This study investigates the temperature- and laser-dependent vibrational properties of silver oxovanadate (α-Ag₃VO₄) obtained via coprecipitation. Scanning electron microscopy, powder X-ray diffraction, and Raman scattering characterized the sample at room temperature. The α-Ag₃VO₄ was synthesized in the monoclinic phase (α-phase) with a C_2/c space group and exhibited a spherical nanoparticle morphology. Furthermore, a theoretical calculation on α-Ag₃VO₄ was performed using Density Functional Theory (DFT), and comparing the theoretical and experimental Raman active frequency results at room temperature demonstrated a good agreement. Laser-dependent Raman spectroscopy showed that the spectral characteristics corresponded to either α-Ag₃VO₄ or a mix of β-Ag₃VO₄ and β-AgVO₃, depending on the applied laser power. Raman analysis revealed reversible α↔β transitions in Ag₃VO₄, with enhanced β-AgVO₃ formation at elevated temperatures, thereby establishing a clear correlation between temperature- and laser-induced phase behavior and underscoring its potential for optoelectronic phase control. The laser- and temperature-induced structural modifications in α-Ag₃VO₄ spherical nanoparticles provide insights into their phonon properties and open new possibilities for laser power-dependent applications, particularly for optoelectronic applications.