Tuning the ferroelectric and piezoelectric properties of 0.91Pb(Zn _1/3Nb_2/3)O₃-0.09PbTiO₃ single crystals and lead zirconate titanate ceramics by doping hydrogen

Systematically experimental investigations were conducted on H-doped 0.91Pb(Zn_1/3Nb_2/3)O₃-0.09PbTiO₃ (PZNT) single crystals and lead zirconate titanate (PZT) ceramics. The experimental results show that doping hydrogen with appropriate content advances the ferroelectric and piezoelectric properties effectively. For example, when trapped hydrogen concentration was C_t = 1.7 wppm in the H-doped PZNT single crystals, the remanent polarization P_r and piezoelectric constant d₃₃ increased by 80% and 41.7% in comparison with the H-free samples, respectively, to 28.8 μC/cm² and 391 pC/N. However, high hydrogen concentration damages the ferroelectric and piezoelectric properties. The remanent polarization P_r and piezoelectric constant d ₃₃ of the H-doped PZNT single crystals decreased to 0 μC/cm ² and 24 pC/N, respectively, when C_t = 3.1 wppm. The H-doped PZT ceramics exhibited the same behavior, where the values of P _r and d₃₃ increased respectively by 45.3% and 27.3% to 48.1 μC/cm² and 420 pC/N, when C_t = 1.1 wppm, and decreased to 0 μC/cm² and 84 pC/N, respectively, as C_t increased to 2.1 wppm. Hydrogen also increases the dielectric constant and dielectric loss for both ferroelectric materials. The experimental results indicate that doping hydrogen into ferroelectric materials is a feasible technique to tune the ferroelectric and piezoelectric properties effectively, furthermore as a subsequent treated technology for the ferroelectric product.