Effect of the processing temperature on the electrical properties of lead-free 0.965Bi(0.5)Na(0.5)TiO(3)-0.035BaTiO(3) piezoelectric ceramics synthesized by sol-gel method

摘要

In this work, lead-free 0.965Bi(0.5)Na(0.5)TiO(3)-0.035BaTiO(3) (BNT-BT) piezoelectric ceramics were synthesized by a sol-gel process. X-ray diffraction pattern of the BNT-BT samples revealed that powder calcined at 600 degrees C, exhibit a pure perovskite structure. Scanning electron microscopy (SEM) was used to find the surface morphology and grain size of the investigated ceramics. At an optimized sintering temperature of 1150 degrees C, well-saturated ferroelectric (P-E) hysteresis loops with high remnant polarization (P-r=34.8 mu C/cm(2)) and low corrosive field (E-c=23kV/cm) were obtained. Electric field-induced strain of 0.137% with a dynamic piezoelectric coefficient (d(33)(*)=196pm/V) was observed under 75kV/cm drawing field. In addition, high static piezoelectric constant (d(33)=138pC/N) was recorded for the sample sintered at 1150 degrees C. This value of d(33) is comparable to that of BNT-based bulk piezoelectric ceramics.