Comprehensively enhanced strain performance in PIN-PMN-PT ferroelectric ceramics via composition and orientation engineering

Abstract

Excellent overall strain performances (i.e., low hysteresis, giant strain, and wide temperature span) are highly desirable in commercial high-precision displacement actuators to satisfy different application scenarios. However, any single means, e.g., compositional design or orientation engineering can hardly achieve the overall improvement of strain properties in ceramics. In this work, an approach of integrating compositional design (Sm and Mn co-doping) and orientation engineering (<001>-textured) is proposed to enhance the strain performance of 0.27Pb(In1/2Nb1/2)O3-0.40Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PIN-PMN-PT) comprehensively. Initially, with the co-doping of Sm and Mn, the hysteresis of PIN-PMN-PT is substantially decreased to approximately 0.43 times that of the undoped material. Subsequently, 5 wt% BaTiO3 (BT) templates were added during the tape-casting process to orient the grains in 1 mol% Sm and Mn-doped PIN-PMN-PT ceramics. This resulted in a unique "4R" domain configuration with a reduced domain size of 0.13 µm. As a result, the domain wall energy was lowered, and the strain strength was increased to 0.35% at 70 kV/cm with low hysteresis to 8.94%. Moreover, the "clamping effect" in textured ceramics generates additional stress due to the lattice mismatch between the matrix grains and the BaTiO3 template, which inhibits the rhombohedral to the tetragonal phase transition. In addition, the fluctuation of strain value was only 8.5% over a wide temperature range of 30–150 °C, demonstrating excellent temperature stability. As a result of the combined effect of ion doping and orientation engineering, the overall strain performance in PIN-PMN-PT has been improved, providing a novel approach to designing superior and practical displacement actuators.