Electromechanical properties of relaxor ferroelectric foams

Three-dimensional finite element models are developed to characterize the complete electromechanical properties of relaxor ferroelectric-based foams. It is demonstrated that microstructural features such as porosity volume fraction and connectivity play significant roles in determining the elastic, dielectric, and piezoelectric properties of relaxor foams. Furthermore, piezoelectric figures of merit such as the coupling constant (K_t), the hydrostatic strain coefficient (d_h), and the hydrostatic figure of merit (d _hg_h) of (PMN-PT based) relaxor foams are significantly higher (by 40%, 900%, and 3000%, respectively, for 3-3 type foams with 50% porosity) than those observed in equivalent (PZT-7A based) traditional piezoelectric foams.