Polarized Raman spectra of tetragonal pure ZrO2 measured on epitaxial films -: art. no. 144302

The actual ambiguity in the interpretation of the Raman-active vibrations of tetragonal ZrO2 is discussed as a factor impeding progress in long-standing investigations of the polymorphism of zirconia. The reliable symmetry assignment of these vibrations is proposed by analyzing a polarized light scattering from single-crystal grains of epitaxial films of pure t-ZrO2 grown on monocrystalline Al2O3 samples. The interrelations between the Raman spectrum of t-ZrO2 and the relevant phonons of c-ZrO2 are considered, implying the A(1g) vibration as a soft mode driving the tetragonal-cubic transformation.