Raman scattering and fluorescent behaviors in Ba0.96Nd0.0267Ti(1-x)WxO3 (x=0.00 and x=0.05) ceramics

This paper reports on the Raman spectroscopy and the photoluminescence spectra of Nd- and W- doped BaTiO3 (BT) ceramics prepared using the molten-salt method. The samples were subjected to annealing at a temperature of 900 degrees C. Raman spectroscopy was carried out at room temperature on doped ceramics and pure BT. The incorporation of Nd3+ for Ba2+ in A site and W6+ for Ti4+ in B site into BT lattice was also discussed. Moreover, we controlled the frequency and damping of the main optic modes. No significant change was observed in the frequency and damping. But the only frequency of A(1)[TO3] mode was slightly sensitive to the Nd and W doping. This could reflect the effect of these ions on the Ti site, since this mode corresponds to a distortion of O octahedron around the central Ti ion. In addition, three different exciting laser lines were used for enlightening the Nd3+ emission effect and the contribution of the luminescence processes in the abnormal Raman spectra recorded for 785 nm. These abnormal Raman signals originate from a fluorescent effect corresponding to F-4(5/2,3/2) -> I-4(9/2) transitions of Ba-site Nd3+ ions. This behavior is confirmed by photoluminescence data at room temperature under 514.5 nm excitation via the presence of two peaks located at 880 nm and 909 nm corresponding to the F-4(5/2,3/2) -> I-4(9/2) transition levels, respectively, which also showed a decrease in the intensity of emission spectra following the incorporation of W6+ ions into the Ti site. The fluorescent signals were so intense that they overwhelmed the traditional Raman spectra of our compounds. (C) 2021 Published by Elsevier B.V.

Automated summary

This study reports on the Raman spectroscopy and photoluminescence spectra of Nd- and W-doped BaTiO3 ceramics prepared using the molten-salt method. The incorporation of Nd3+ and W6+ ions into the BT lattice was analyzed, with a focus on their effects on the Ti and Ba sites. The abnormal Raman signals observed were attributed to a fluorescent effect from Ba-site Nd3+ ions, with intense fluorescent signals overwhelming the traditional Raman spectra.