The electrical properties of low-temperature sintered PMN-PT electrostrictive ceramics by LiF modification

LiF was introduced into PMN-PT electrostrictive ceramics as a sintering aid to lower the firing temperature, and its influence on the electrical properties and microstructures were investigated. The sintering temperature was effectively shifted down by the addition of LiF, which could be attributed to the liquid phase sintering mechanism. Dense microstructures with facet grains were found in the modified compositions, where the existence of secondary phase was not detected. The LiF-doped samples showed the decreased T _m , causing the enhanced relaxor behavior at room temperature, while the T _m increased with the increasing PT content. Excellent electric field-induced strain performance of d ₃₃ ^* (S _max /E _max ) ~ 526 pm/V (E = 1 kV/mm) with extremely low hysteresis ~3 % of S–E curves was achieved in low-temperature sintered electrostrictive ceramics. This result makes the ceramics much attractive for applications in multilayer-structured actuators.