Investigation of single and multidomain Pb (In_0.5Nb _0.5) O₃-Pb (Mg_1/3Nb_2/3)O₃ - PbTiO₃ crystals with mm2 symmetry

The piezoelectric properties of Pb (In_0.5Nb_0.5) O₃ -Pb (Mg_1/3Nb_2/3) O₃ - PbTiO ₃ crystals with various engineered domain configurations were investigated. Rhombohedral and monoclinic/orthorhombic crystals poled along their crystallographic [011] directions were found to possess macroscopic mm 2 symmetry, with "2R" and "1O" domain, respectively. Crystals with the "2R" domain configuration were found to exhibit high extensional piezoelectric coefficients d33 (∼1300 pC/N) and d32 (∼-1680 pC/N), while crystals with the "1O" configuration possessed high shear coefficients d15 (∼3500 pC/N) and d24 (∼2070 pC/N), with relatively low extensional piezoelectric coefficients d33 (∼340 pC/N) and d32 (∼-260 pC/N). The observed results were explained by "polarization rotation" model, as related to their respective domain configurations.