Force constant calculation from Raman and IR spectra in the three non-cubic phases of BaCeO3

Raman spectroscopic data for BaCeO3 were modeled with the use of a small se t of force constants in its three phases (Pnma, Imma and R (3) over barc) u sing experimental IR and Raman data. An IR reflectance spectrum of BaCeO3 i n its Pnma phase is provided for the first time. Raman band symmetry assign ments in the Pnma phase were re-examined and the assignments of Genet et al . were confirmed. The distribution of the Raman bands of the Pnma phase bet ween the zone center and X point in Imma is provided and band assignments w ere extended to the Imma and R (3) over barc phases. Calculated values for both Raman- and IR-active modes are provided in the three phases. The varia tions in force constants throughout the phase transitions are briefly discu ssed. Copyright (C) 2001 John Wiley & Sons, Ltd.