Raman and infrared spectra of brookite (TiO2): Experiment and theory

The zone-center phonons and the frequency-dependent dielectric function of the brookite phase of TiO2 are studied experimentally by means of polarized Raman and infrared spectroscopy. The Raman- and infrared-active modes are unambiguously identified by symmetry. The mode frequencies are in good agreement with those predicted by the density function calculations of lattice dynamics.