2023-10-302023-10-302017CASTRO, T. J. et al. Investigation of additional Raman modes in ZnO and Eu0.01Zn0.99O nanoparticles synthesized by the solution combustion method. Journal of Alloys and Compounds, Amsterdam, v. 691, p. 416-421, 2017. DOI: 10.1016/j.jallcom.2016.08.297. Disponível em: https://www.sciencedirect.com/science/article/pii/S0925838816326998. Acesso em: 4 set. 2023.0925-8388e- 1873-4669https://www.sciencedirect.com/science/article/pii/S0925838816326998In this study, we report on the origin of Raman additional modes (AM) in ZnO and Eu0.01Zn0.99O nanoparticles (NPs) synthesized by the solution combustion method (SCM). The as-produced samples were thermally annealed at different temperatures and under different conditions (air, N2-flow and He-flow). The as-produced NPs exhibited the characteristic color (salmon) of N-doped ZnO. Typical patterns of ZnO wurtzite were found by X-ray diffraction data and no evidences of additional phases were detected. Raman spectra of as-produced ZnO and Eu0.01Zn0.99O NPs showed AM features usually found in N-doped ZnO. These features disappeared after thermal annealing in air, but they do not disappeared after thermal annealing in N2- and He-flow. Effects of Eu-doping on AM modes were observed, indicating that co-doping with Europium can be used to increase the Nitrogen solubility in ZnO. Using the Raman data the maximum N-content in Eu0.01Zn0.99O NPs was estimated in 1018 cm−3. Our results concerning thermal annealing at different conditions indicated that it is unlikely that Zni-Oi complexes are the origin of the ∼510 cm−1 AM, as it is currently proposed in the literature. Instead, the Raman AM features observed in this study were attributed to disorder activated Raman modes favored by N-doping.engAcesso RestritoNanostructured materialsRare earth alloys and compoundsChemical synthesisPhononsOptical spectroscopyArtigo10.1016/j.jallcom.2016.08.297