Polarized Raman scattering spectra were obtained from oriented single crystals of yttria-doped material. The temperature and dopant dependences of the Raman spectra strongly suggested that many structures in the spectra of this material were induced by defect spaces which contained an O2- vacancy. The contribution, to the frequency distributions of Raman-active modes, which arose from the entire Brillouin zone were estimated from the imaginary part of a simple projection, of the phonon displacement-displacement Green's functions of undoped crystals, onto several defect spaces. The observed spectra could be explained by linear combinations of the calculated frequency distributions for a defect space that consisted of 4 metal ions, and for one which consisted of 6 next-nearest neighbor O2- ions surrounding an O2- vacancy. The Brillouin scattering spectra were also measured in order to calculate phonon dispersion curves.

A.Nakajima, A.Yoshihara, M.Ishigame: Physical Review B, 1994, 50[18], 13297-307