Dielectric behavior, band gap, in situ X-ray diffraction, Raman and infrared study on (1 - X)BiVO₄-x(Li_0.5Bi _0.5)MoO₄ solid solution

The phase transition in the (1 - x)BiVO₄-x(Li _0.5Bi_0.5)MoO₄ solid solution was first confirmed by the in situ X-ray diffraction method. The merging of the (2 0 0) and (0 2 0) diffraction peaks in the X-ray diffraction data, and the overlapping of the δ_s(VO₄) and δ_as(VO ₄) modes for Raman and Infrared spectra of x = 0.06 sample were observed at 110-115 °C. The splitting of infrared bands at around 325 cm^-1 for x = 0.125 sample was revealed at -10 °C. The dielectric permittivity peaks as a function of temperature can be observed at high frequencies (>10 kHz), which is corresponding to the ferroelastic phase transition. In the monoclinic solid solution region, the band gaps were found to lie between 2.2-2.35 eV a range of interest as photo-catalytic materials.