Raman spectroscopy and lattice-dynamical calculations of Sc3CrO6single crystals

Abstract

Single crystals of Sc 3 CrO 6 were grown by high temperature solution growth method. They were studied using x-ray single crystal diffractometry, scanning electron microscopy (SEM) with x-ray microprobe analysis and micro-Raman spectroscopy. The crystal structure was refined as rhombohedral one with space group R3, which confirms that it belongs to the Mg 3 TeO 6 -structural type family. In the polarized Raman spectra collected at room temperature all 9A g + 9E g Raman-allowed phonon modes were observed. The experimentally determined frequencies are compared to the results of lattice-dynamical calculations (LDC) using a shell model. The Raman spectra, obtained with increasing temperature up to 600 • C, do not provide direct indication for structural phase transition. The decrease with increasing temperature of the relative intensity of five A g lines compared to the rest ones, however, suggests a possible structural phase transition from R3 to R3c above the investigated temperature region.

Symmetries of modes in Ni3V2O8: Polarized Raman spectroscopy and ab initio phonon calculations

“…A detailed Raman and FTIR investigations on Na 2 Ti 3 O 7 enabled assignments of all the vibrational modes, which is useful for technological applications of the compound . Polarized Raman investigation has explained the temperature‐dependent phase transitions in single crystals of Sc 3 CrO 6 , and assignment of not only phonons but also magnons was done in CuB 2 O 4 using polarized Raman spectroscopy . It has been used to understand the mechanism of ferroelectric to paraelectric transition in bulk BaTi 2 O 5 as well as in thin films .…”

Decoupling the Chemical and Mechanical Strain Effect on Steering the CO2 Activation over CeO2-Based Oxides: An Experimental and DFT Approach

“…Important from the catalysis perspective is the defect region (550–600 cm –1 ), which is associated with the LO mode (F 1u symmetry). Even though this symmetry is Raman inactive, a relaxation of selection rules , makes the LO mode visible. The presence of defects causes a significant lowering in symmetry and thus relaxation in selection rules.…”

“…Important from the catalysis perspective is the defect region (550−600 cm −1 ), which is associated with the LO mode (F 1u symmetry). Even though this symmetry is Raman inactive, a relaxation of selection rules 63,64 of the Raman spectral defect region led to quantitative estimation of the O v /F 2g ratio for the pristine, DBM, and WBM Ce−La−10Cu−O oxides (Figure S4). This ratio is considered as a good descriptor of the O v population in the oxide.…”

Hot pressing of Yb:Y2O3 laser ceramics with LiF sintering aid

“…9. For C-type sesquioxides, at the center of the Brillouin zone, the set of irreducible representations is Г = 4Ag + 4Eg + 14Fg + 5A2u + 5Eu + 16Fu, among which the Ag, Eg, and Fg modes are Raman-active, Fu is IR active and A2u and Eu are silent [30,31]. The number of the observed modes for the ceramic (12) is less than the theoretical one (22).…”