Pressure-dependence Raman spectroscopy and the lattice dynamic calculations of Bi2(MoO4)3 crystal

This work reports a pressure-dependent Raman spectroscopic study and the theoretical lattice dynamics calcu-lations of a Bi2(MoO4)3 crystal. The lattice dynamics calculations were performed, based on a rigid ion model, to understand the vibrational properties of the Bi2(MoO4)3 system and to assign the experimental Raman modes under ambient conditions. The calculated vibrational properties were helpful to support pressure-dependent Raman results, including eventual structural changes induced by pressure changes. Raman spectra were measured in the spectral region between 20 and 1000 cm-1 and the evolution of the pressures values was recorded in the range of 0.1-14.7 GPa. Pressure-dependent Raman spectra showed changes observed at 2.6, 4.9 and 9.2 GPa, these changes being associated with structural phase transformations. Finally, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed to infer the critical pressure of phase transformations undergone by the Bi2(MoO4)3 crystal.

Automated summary

This study investigates the pressure-dependent Raman spectroscopic properties of a Bi2(MoO4)3 crystal and performs theoretical lattice dynamics calculations to understand its vibrational characteristics. The calculated properties are used to support the experimental Raman results and identify structural changes induced by pressure. Raman spectra were measured in a range of pressures, and changes associated with structural phase transformations were observed. Principal component analysis and hierarchical cluster analysis were employed to determine the critical pressure for phase transformations in the Bi2(MoO4)3 crystal.