Crystallographic dependence of internal bias in domain engineered Mn-doped relaxor-PbTiO₃ single crystals

The incorporation of acceptor dopants and the resulting internal bias in Pb(Zr,Ti)O₃ (PZT) piezoelectric ceramics lead to reduced electrical and mechanical losses, but at the expense of decreased electromechanical properties. Analogous to PZTs, acceptor doped relaxor-PbTiO₃ (relaxor-PT) single crystals show an improved mechanical quality factor (decreased mechanical loss), but with a minimal impact on the electromechanical properties. In this research, the internal bias and associated impacts on electromechanical properties were studied in Mn-doped Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (Mn:PIN-PMN-PT) single crystals, showing strong crystallographic orientation dependent behaviors. By active control of defect dipoles through domain engineering, different defect dipole configurations were obtained (defect dipole engineering), leading to the unique characteristics of relaxor-PT single crystals when compared to the conventional polycrystalline ferroelectric ceramics.