Hysteresis-free electrostrictive response in PMN-PT ceramics and multilayer actuators

Relaxor-PbTiO₃ solid solutions, particularly (1−x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT), are essential multifunctional materials widely used in advanced electronic devices due to their superior ferroelectric, piezoelectric, and electro-optic properties. Beyond conventional piezoelectricity, PMN-PT is a promising candidate for electrostrictive ceramics, offering intrinsic, nearly hysteresis-free strain critical for ultra-high precision actuation. Here, we report 4 mol% Nd3+-doped 72PMN-28PT ceramics, in which local structural heterogeneity induced by Nd3+ disrupts long-range ferroelectric order, yielding almost pure intrinsic electrostrictive response. Optimized pre-sintering ensures consistent dielectric and electromechanical performance despite minor phase variations. Under 30 kV/cm, the fitted electrostrictive coefficient Q₃₃ reaches ∼0.0185 m4/C2 and bipolar maximum strain S_max approaches 0.1%. In bias fields of 10–30 kV/cm, S_max exceeds 0.05%, with hysteresis below 5% and excellent linearity. Multilayer ceramic actuators fabricated from this composition achieve ∼8 μm displacement with high stepping precision and stability, demonstrating their potential for precision micro-displacement platforms, semiconductor processing equipment, and adaptive optical systems.