Moreira, Roberto LuizLobo, Ricardo P. S. M.Ramos, Sérgio L. L. M.Sebastian, Mailadil T.Matinaga, Franklin MassamiRighi, ArieteDias, Anderson2019-05-022019-05-022018MOREIRA, R. L. et al. Raman and infrared spectroscopic investigations of a ferroelastic phase transition in Ba2ZnTeO6 double perovskite. Physical Review Materials, v. 2, v. 5, p. 054406, maio 2018. Disponível em: <https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.2.054406>. Acesso em: 7 mar. 2019.2475-9953http://www.repositorio.ufop.br/handle/123456789/11163The low-temperature vibrational properties of B a 2 ZnTe O 6 double-perovskite ceramics obtained by the solid-state route were investigated by Raman scattering and Fourier-transform infrared reflectivity. We found that this material undergoes a reversible ferroelastic phase transition at around 140 K, well compatible with a recently proposed rhombohedral-to-monoclinic structural change that would occur below 165 K. Complementary calorimetric measurements showed that the phase transition has a first-order character, with an entropy jump compatible with a displacive mechanism. The vibrational spectra show clearly the splitting of the doubly degenerate E modes into nondegenerate representations of the low-symmetry phase. In particular, the lowest-frequency Raman mode presents soft-mode behavior and splits below the critical temperature, confirming the in-plane ferroelastic deformation in the low-temperature phase.en-USrestritoArtigo publicado em periodicohttps://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.2.054406https://doi.org/10.1103/PhysRevMaterials.2.054406