Enhanced piezoelectric and dielectric properties of Pb(Yb_1/2Nb_1/2)O₃–Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ crystals by combining alternating and direct current poling

As one of domain engineering methods, alternating current poling (ACP) has been proved a convenient, effective, economical method for the enhancement of the dielectric and piezoelectric properties of relaxor–PbTiO₃ (PT) ferroelectric crystals. However, a shortcoming of ACP is that there are some non-rotational domains. To further improve the potential piezoelectric properties of relaxor–PT crystals, a modified poling method, combining alternating and direct current poling (ACP + DCP), was used for improving the piezoelectric properties of Pb(Yb_1/2Nb_1/2)O₃–Pb(Mg_1/3Nb_2/3)O₃ (PYbN–PMN)–PT ferroelectric crystals. Compared with separate DCP and ACP, the piezoelectric coefficient d₃₃ of [001]-oriented PYbN–PMN–PT crystals increased by 51% and 15% using ACP + DCP, respectively, indicating that applying an appropriate DCP on ACP samples is beneficial to further improve the piezoelectric properties. The domain analysis reveals that the full rotation of polarization, regular domain patterns, and domain boundaries are the key factors for the enhancement of piezoelectric and dielectric properties. We established the relationship between the position of the (300)_c peaks, reflecting the degree of the stretch of the lattice, and piezoelectric properties. This work indicates that combining alternating and direct current poling methods is a better poling strategy for enhancing the piezoelectric properties of relaxor–PT ferroelectric crystals compared with separate DCP and ACP methods.