Temperature-induced crystallinity and vibrational properties in samarium orthovanadate
Phys. Rev. B 101, 174112 – Published 21 May, 2020
DOI: https://doi.org/10.1103/PhysRevB.101.174112
Abstract
The Samarium orthovanadates particles were prepared using the sol-gel method, and the effect of sintering temperature on the crystallinity was studied in detail through x-ray diffraction (XRD) and the Rietveld refinement of the obtained XRD data. Density functional theory (DFT) based calculations were used to describe the dynamic properties in Samarium orthovanadate. The data obtained from the DFT calculations were made instrumental in confirming the vibrational properties, and both the Raman and infrared modes obtained through the experiments. Temperature-dependent Raman spectroscopy was used to provide a deeper insight into all the eigenmodes and their behavior with varying temperature. A temperature-dependent (experiment) and pressure-dependent (DFT) Raman spectra were produced for the investigation of eigenmodes in the samples. A correlation between the two methods was seen, and the alignment between the two data sets was found to be ineluctable. The Grüneisen parameter of individual modes were calculated with the aid of the theoretically obtained variation in the Raman shift with respect to the bulk modulus. Ultraviolet-visible spectroscopy of the samples was explored to study possible correlation with temperature, and theoretical bandgaps were obtained through standard DFT and hybrid exchange-correlation functional calculations. Photoluminescence spectroscopy was performed in the hopes of unveiling possible applications of the material.
