Lattice vibrations and bulk properties of ceramics-forming materials: Piezoeffect in SiC and elasticity of ZrO2

The role of lattice vibrations in the crystal properties related to the hom ogeneous strains is discussed. Such properties depend on the individual pho non characteristics measurable by vibrational spectroscopy. So, being appli cable to powderlike samples, it can provide an indirect information on thos e bulk characteristics which cannot be directly measured for such samples. The piezoelectricity of cubic SiC, and the elasticity of tetragonal ZrO2 ar e considered along with the phonon spectra. Thus the mechanism of the polar ization of sphalerite-like materials is elucidated; a contradiction between the elastic properties of the t-ZrO2 lattice and the conventional interpre tation of its Raman spectra is revealed. (C) 1999 Kluwer Academic Publisher s.