Using Raman scattering to study the doping effect and low-temperature phase transition of Li_(0.01)K_(0.99)NbO_3 ceramics

摘要

This article, reports on the results of low-temperature Raman scattering from Li_(0.01)K_(0.99)NbO_3, ceramic in the rhombohedral-orthorhomic phase transitions. The spectral pattern of Li_(0.01)K_(0.99)NbO_3 indicated that the phase transition occurred at around 150K during cooling and at 190K during heating. The observed spectra are discussed in terms of relationship to the translational and vibrational modes of K atoms against the NbO_6 octahedron, the vibrational or librational mode of the oxygen octahedron and the internal stretching mode of NbO_6. The phase transition temperature of Li_(0.01)K_(0.99)NbO_3 is lower than that of pure KNbO_3 by approximately 60 K. These phenomena are associated with the Li-doped effect.