Lattice dynamics of β-V 2 O 5 : Raman spectroscopic insight into the atomistic structure of a high-pressure vanadium pentoxide polymorph

We report here the Raman spectrum and lattice dynamics study of a well-crystallized β-V 2 O 5 material prepared via a high-temperature/high-pressure (HT/HP) route, using α-V 2 O 5 as the precursor. Periodic quantum-chemical density functional theory calculations show good agreement with the experimental results and allow one to assign the observed spectral features to specific vibrational modes in the β-V 2 O 5 polymorph. Key structure-spectrum relationships are extracted from comparative analysis of the vibrational states of the β-V 2 O 5 and α-V 2 O 5 structures, and spectral patterns specific to the basic units of the two V 2 O 5 phases are proposed for the first time. Such results open the way for the use of Raman spectroscopy for the structural characterization of vanadium oxide-based host lattices of interest in the field of lithium batteries and help us to greatly understand the atomistic mechanism involved in the α-to-β phase transition of vanadium pentoxide.