Reversible Structural Phase Transition in ZnV₂O₆ at High Pressures

Abstract

The structural and electrical properties of ZnV 2 O 6 under high pressure have been studied using Raman spectroscopy, in situ angle dispersive X-ray diffraction (ADXRD), and alternating current (AC) impedance spectroscopy. The results of Raman spectra indicate that ZnV 2 O 6 undergoes a reversible structural change around 16.6 GPa, as evidenced by the appearance of new peaks. The results of Rietveld refinements from in situ ADXRD data indicate that the monoclinic symmetry (C2/m) is retained up to 16.0 GPa and the C2 phase comes to coexist between 16.0 and 16.9 GPa. Above 16.9 GPa, the high-pressure phase can be distinguished only as the C2 structure. The transformation process from the C2/m phase to the C2 phase is mainly caused by the more distorted ZnO 6 octahedra and VO 6 octahedra at higher pressures. The equal bond distances Zn−O2 and V−O3 in the C2/m phase become unequal in the C2 phase. Furthermore, the measurements of the AC impedance spectroscopy of ZnV 2 O 6 reveal obvious changes in its electrical transport properties at 14.1 GPa which could correspond to the observed phase transition in the Raman and ADXRD measurements. The combined analyses of experimental results suggest the occurrence of a reversible structural phase transition of ZnV 2 O 6 around 16.0 GPa.

Mo-doped ZnV2O6/reduced graphene oxide photoanodes for solar hydrogen production

“…Figure 2b displays the Raman spectrum recorded to further confirm the presence of the dopants and rGO in the prepared ZnV 2 O 6 :Mo/rGO composite. The obtained Raman bands are in complete agreement with previous studies for ZnV 2 O 6 [38]. However, a slight shift towards lower wavenumbers was observed for the doped sample suggesting that the Mo with a larger ionic radius (59 pm) partially substitutes the V (54 pm) in the ZnV 2 O 6 lattice [39].…”

A Bifunctional 2D Interlayered β‐Cu2V2O7/Zn2V2O6 (CZVO) Heterojunction for Solar‐Driven Nonsacrificial Dye Degradation and Water Oxidation

“…Few peaks remain unassigned due to limited literature, as more insight is required for their proper assignment. [40] As expected, the Raman spectrum of CZVOopt (red line) exhibits mixed bands of ZVO and CVO. The apparently combined bands in CZVO-opt Raman spectrum caused a distinct blue-shift from 139 and 911 cm À1 to 156 and 923 cm À1 for bare CVO (highlights under brown circle).…”

A 1D Honeycomb‐Like Amorphous Zincic Vanadate for Stable and Fast Sodium‐Ion Storage

“…The resemblance of transform infrared spectroscopy (FTIR) and Raman spectra further indicates the amorphous ZVO‐AH is zincic vanadate material instead of a mixture of ZnO and VO x (Figure S15, Supporting Information). The characteristic Raman perks arise at 862 and 910 cm −1 , corresponding to antisymmetric stretching vibration and stretching vibration modes of VOV and VO, respectively (Figure b) . Obviously, the Raman bands of ZVO‐AH shift to lower wavenumbers and become broader and weaker, which indicates the distorted lattices with variations in bonding length and angle, and the short‐range order arise together in ZVO‐AH sample …”