Low temperature phase transition of Li0.12Na0.88NbO3 studied by Raman scattering

In this article, we will report the low temperature Raman studies of Li0.12 Na0.88NbO3 ceramics at the ferroelectric-ferroelectric phase transitions. T he spectral pattern indicates the phase transition occurs at 200 K in the c ooling process and at 280 K on heating. The observed spectra are discussed as they relate to the internal stretching modes of the NbO6 octahedron and cation translation modes. The temperature-dependent spectra show that the p hase transitions may involve the rearrangement of Na+ cation, the relative orientation of the NbO6 octahedral, and the displacement of Nb ions. (C) 20 00 American Institute of Physics. [S0021-8979(00)7412-0].