LIU Haitao, LI Ying , DU Huiling, CHEN Xifeng

(Dep. Material science and engineering, Xi' an Univers ity of Science and Technology, 710054)

Abstract: Raman scattering spectroscopy is lesser used to inves tigate the phase trans ition of lead-free piezoceramic. Us ing Raman scattering spectra and Group theory,the lattice vibration and structural phase trans ition of (Na _0.5Bi_0.5)(1- x)TiO₃- Ba_xTiO₃ (abbr. NBT- BT) crystal were studied in this paper.The results indicate that with the increase doping amount of Ba ^{2 +}, the optical phonon peak at 521.4cm^{- 1}splits into two peaks clearly and the higher frequency phonon mode shifts to the higher frequency; For x=0.6, the soft mode is soften with the increas ing of temperature at 460~620cm^{- 1}. So that, Raman scattering analys is is an effective way to estimate the phase trans ition trend in NBT- based ceramics .

Keywords: Sodium- bismuth titanate; Raman scattering; Structural phase trans ition