Dielectric behavior, band gap, in situ X-ray diffraction, Raman and infrared study on (1 − x)BiVO4–x(Li0.5Bi0.5)MoO4 solid solution

Abstract

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(VO₄) 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.