Polarized Raman spectroscopic study and investigation of phonon modes of Co3(VO4)2 at variable thermodynamic conditions

Polarized Raman spectroscopic investigation on oriented single crystal of orthovanadate Co3(VO4)2 is carried out. We have observed and identified symmetries of 32 out of 36 expected Raman active modes of Co3(VO4)2 in different polarization directions. Evolution of frequencies of observed Raman active modes in Co3(VO4)2 are also investigated under variable thermodynamical conditions. The isothermal high pressure Raman spectroscopic investigation indicates stable orthorhombic (Cmca) structure up to 15.7 GPa consistent with reported literature. The isobaric high temperature Raman spectroscopic investigation up to 823 K is used to estimate the total anharmonicity of all the observed Raman active modes. Evolution of Raman spectra indicates structural stability in the temperature and pressure range investigated. By a combination of high pressure and temperature dependent Raman spectroscopic data, the analysis of anharmonicity of observed Raman modes are calculated. Our measurements indicate dominant contribution of three phonon decay process for almost all the observed Raman active modes in Co3(VO4)2. The anharmonicity information along with symmetry of these observed modes can be used as an input in the analysis of expected spin-phonon anomalies around the magnetic transition in Co3(VO4)2 in future investigations.