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 homogeneous strains is discussed. Such properties depend on the individual phonon characteristics measurable by vibrational spectroscopy. So, being applicable to powderlike samples, it can provide an indirect information on those bulk characteristics which cannot be directly measured for such samples. The piezoelectricity of cubic SiC, and the elasticity of tetragonal ZrO2 are considered along with the phonon spectra. Thus the mechanism of the polarization of sphalerite-like materials is elucidated; a contradiction between the elastic properties of the t-ZrO2 lattice and the conventional interpretation of its Raman spectra is revealed.