Temperature‐Dependent Phase Evolution of LaVO4 via Solid‐State Synthesis Route

Lanthanum ortho ‐vanadate (LaVO 4 ) is a wide bandgap semiconducting material suitable for various applications especially for photocatalytic activities. In most cases, the synthesis of LaVO 4 involves concentrated acidic treatments and very high reaction temperatures for long durations. The present work establishes an easy route to synthesize LaVO 4 at a relatively lower temperature and short dwelling time via solid‐state reaction of the precursors of lanthanum acetate hydrate and vanadium acetylacetonate. The thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) analyses of the precursor mixture indicate a phase transition above 415 °C. The Rietveld structure refinement of the X‐ray diffraction data of the precursor mixture, obtained after heat treatment at 500 °C, confirms the formation of the monoclinic ( m ‐) phase of LaVO 4 corroborating the predictions from the TGA‐DSC analysis. The occurrence of internal vibrational modes related to the VO 4 tetrahedron in the Raman spectra suggests the onset of the nucleation of the m ‐LaVO 4 phase at a lower temperature. The external modes representing the vibrations of the molecule as a whole are profound at higher temperatures. The coexistence of LaO as well as VO bond vibrations observed in the Fourier transform infrared spectroscopy further confirmed the formation of bonding between the atoms of the molecule.