Determination of ferroelastic phase transition temperature in BiVO4 by Raman spectroscopy

Abstract

BiVO4, a well-known photocatalyst and industrial pigment, undergoes a reversible ferroelastic phase transition at about 530 K. In this framework, identifying techniques that can accurately measure the signature of the ferroelastic phase transition would be very useful. We find that the most intense Raman band of BiVO4 ceramics at 829 cm−1 shows an interesting temperature dependency, as it is non-linear in the investigated range of 298–898 K, while two distinct linear regimes can be distinguished below and above 550 K. The point of the intersection after extrapolating the two linear regions is 530 K, which happens to be the ferroelastic phase transition temperature of BiVO4 from monoclinic to tetragonal phase.