Ba(Ti0.96Sn0.04)O3陶瓷的物性研究

采用传统固相反应法制备了Ba(Ti_0.96Sn_0.04)O₃无铅压电陶瓷, 对其压电性能、介电性能、铁电性能和微观结构等进行了研究。研究发现, 原料以及制备工艺对Ba(Ti_0.96Sn_0.04)O₃陶瓷的压电性质具有较大的影响。与BaTiO₃陶瓷相比, Ba(Ti_0.96Sn_0.04)O₃陶瓷的正交-四方相变温度T_O-T得到了一定的提高, 并且T_O-T附近的热滞只有1.8℃。陶瓷的微观形貌呈现出较为复杂的畴结构, 主要以90°平行带状畴为主, 偶尔有少量不同构型的180°畴。电滞回线呈现为理想的近似矩形饱和形状的曲线, 剩余极化强度P_r为18.9 μC/cm², 矫顽场E_c为 2.5 kV/cm。此外, 非180°畴的翻转是引起陶瓷逆压电常数d₃₃^*的主要因素, 其值可达550 pm/V。

Physical Properties of Ba(Ti0.96Sn0.04)O3 Ceramics

The Ba(Ti_0.96Sn_0.04)O₃ ceramics were prepared through solid-state reaction route. Piezoelectric property, dielectric property, ferroelectric property, and microstructure were investigated. It is found that raw material and processing technique can largely affect the piezoelectric property of the Ba(Ti_0.96Sn_0.04)O₃ ceramics. By comparing with the physical property of pure BaTiO₃ ceramics, Sn doping significantly increases the transition temperature from orthorhombic phase to tetragonal phase (T_O-T) of the Ba(Ti_0.96Sn_0.04)O₃ ceramic to 36.9℃, while the thermal hysteresis at about T_O-T is only 1.8℃. Its microstructure shows complicated domain, mainly composed of simple 90° parallel stripes with a few of different 180° configurations. P-E curve shows ideal square-like and saturated form with remanent polarization P_r of 18.9 μC/cm² and coercive field E_c of 2.5 kV/cm. In addition, it is the non-180°-domain switching that leads large converse piezoelectric constant d₃₃^*, (up to 550 pm/V).