Assignment of Raman-active vibrational modes of MgTiO3

Abstract

MgTiO 3 ceramic sample was synthesized and its Raman spectra were recorded. The Raman-active vibrational modes of MgTiO3 were calculated using first-principle calculations (density functional theory). Based on experimental data and calculation results, the Raman peaks were assigned as 225 cm−1 (Ag), 306 cm−1 (Ag), 398 cm−1 (Ag), 500 cm−1 (Ag), 715 cm−1 (Ag) and 281 cm−1 (Eg), 328 cm−1 (Eg), 353 cm−1 (Eg), 486 cm−1 (Eg), 641 cm−1 (Eg). The assignment was supported by the polarized Raman spectrum. Meanwhile, the symmetry coordinates of MgTiO3 primitive cell were analyzed and employed to expand the Raman-active modes.

A large red-shift in the photoluminescence emission of Mg 1−x Sr x TiO 3

“…Figure 3 shows the MR spectrum of the MTO and MTO:Sr for powders heat treated from 400 • to 700 • C. No Raman active modes of MTO samples heat treated at 400 • C and 500 • C, regardless of doping, are observed, indicating that these samples are Raman inactive and are completely disordered in the short-range. These results are in agreement with the XRD (see Figure 1), and we conclude the structural organization at the long-range and short-range of the MTO phase begins at 600 • C. The group theory for MTO in the rhombohedral structure [22][23][24] predicts the crystals should have 10 distinct vibrational Raman-active modes (5A G + 5B G ), which are observed for the samples heat treated at 600 • C and 700 • C (see Figure 3). All Raman-active modes can be observed for the samples treated at temperatures of 600 • C and 700 • C, which confirms that the MTO and MTO:Sr samples are structurally ordered at the short-range.…”

“…Table 1 Based on our results reported in Table 1, the Eg modes located at 321 cm −1 and 346 cm −1 can be described as the twisting of the O octahedron with the vibrations of Mg and Ti atoms parallel to the xy-plane. The Eg modes located at 480 and 635 cm −1 are due to the anti-symmetric breathing and twisting vibrations of the O octahedra with the cationic vibrations parallel to the xy-plane [7,24]. Another important aspect concerns the Eg modes at 480 cm −1 where both Mg and Ti atoms are involved in the vibration, whereas the mode at 635 cm −1 is associated to the Ti O stretch [24].…”

Effect of (Ca0.8Sr0.2)0.6La0.267TiO3 on Phase, Microstructure, and Microwave Dielectric Properties of Mg0.95Zn0.05TiO3 Synthesized by Polymeric Precursor Method

“…The ilmenite structure of MgTiO 3 is known to exhibit 5A g + 5E g Ramanactive vibrational modes. 25 The vibrations of Mg/Zn and Ti (A g modes) along z-axis appeared at 223.97 cm À1 and 304.84 cm À1 . The other A g modes associated with vibrations of O atoms were observed at 396.36 cm À1 , 496.31 cm À1 , and 714.54 cm À1 .…”

Raman scattering of single crystal Cu2MoS4 nanosheet

“…Accroding to group theory, 10 the A 1 and B 1 phonon branches are Raman active. The B 2 and E branches are both Raman and infrared-active, which are also polarized in the z direction and xy plane respectively.…”

“…10 The small amount of as-obtained samples was homogeneously dissolved to a These authors contributed equally to this work. ethanol, and then deposited on a marked-silicon substrate with gold thin film.…”