Effect of starting raw materials on the dielectric, ferroelectric and electro-shape-memory properties of Mn³⁺ doped (Pb₄₀Sr ₆₀)TiO₃ ceramics

The effect of starting raw materials on the dielectric, ferroelectric and electro-shape-memory properties of 0.5 mol% Mn³⁺ doped (Pb ₄₀Sr₆₀)TiO₃ ceramics was systematically studied. SEM observation showed that the ceramics fabricated from Pb ₃O₄, SrCO₃, TiO₂ and MnCO ₃ possessed the most homogeneous microstructure and the largest grain size. As the macroscopic consequence, such ceramics exhibited large dielectric property and well-developed double hysteresis loop. More interestingly, it showed large digital-like recoverable electrostrain of 0.11 % under the electric field of 3 kV/mm, which can rival the widely used linear piezoelectricity of the hard PZT ceramics. Defect distribution within the large and homogenous grains was analyzed to explore the microscopic origin of the simultaneous domain switching behavior and the digital-like strain properties. Such feature indicated the importance of material processing on the on/off-characterized electromechanical applications.