The paper presents the results of a comparative study of elastic losses and dispersion in dense and porous ferroelectrically “hard” piezoceramics of the same chemical composition based on the lead zirconate titanate (PZT) system. To measure and analyze the real and imaginary parts of the complex elastic parameters, as well as their frequency dependences, we used a previously developed method for analyzing piezoresonance spectra for the fundamental and higher-order resonances of thickness oscillations mode of piezoceramic disks. Experimental samples of dense and porous piezoceramics were prepared using conventional sintering techniques and a modified pore-former burnout method. The study revealed regions of anomalous elastic dispersion in porous piezoceramics, caused by a change in the ratio of the wavelength of resonant oscillations of the piezoceramic element to the spatial heterogeneity scale of its porous microstructure as the frequency increases.
Shvetsov et al. (Wed,) studied this question.