Raman study for BaTiO3 system doped with various concentrations and treated at different temperatures

The BT system with various Sr-doped concentrations (x = 0,0.1,0.2,0.3,0.4,0.5) and treated at different temperatures has been investigated by Raman scattering. Tao new lines, 1060-1065cm(-1), 880-881 cm(-1). have been observed. They are attributed to the first overtones of A(1) (TO3) and E-2 modes respectively. it was found that there are line shifts to a higher wave number for higher frequency lines, and to a lower wave number for lower frequency lines. which is due to increasing disorder. A conclusion can be made that there is a Sr-dependent phase transition. The dynamic process of BT can be partly reflected from its Raman spectroscopy. The size effects of nanocrystallines make it possible that the overtones of high frequencies occurred. (C) 1999 Acta Metallurgica Inc.