The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO(4) (A=Bi, Fe, Cr) and Co(2)V(2)O(7)

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO(4) and Co(2)V(2)O(7) are monoclinic at room temperature, FeVO(4)’s crystal structure is triclinic, and CrVO(4) is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO(4) occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co(2)V(2)O(7) was larger than that of the monoclinic structure BiVO(4). The CTE of the tetragonal structure of BiVO(4) was 15.27 × 10(−6) °C(−1) which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO(4) was 2.84 × 10(−6) °C(−1) and was the smallest.