掺杂三氧化二锑的钛酸铋钠钾陶瓷的显微结构和电学性能

Microstructure and Electrical Properties of Antimony Trioxide Doped Potassium Sodium Bismuth Titanate Ceramics

采用固相合成工艺制备了(1–x)[0.82Bi0.5Na0.5TiO3–0.18Bi0.5K0.5TiO3]–xSb2O3(BNKT–xSb)压电陶瓷,研究了Sb2O3掺杂对BNKT陶瓷的显微结构和电学性能的影响规律。研究表明:Sb2O3掺杂量x小于0.020时,不改变基体的钙钛矿结构,且Sb具有可变化合价,能形成"施主"和"受主"2种掺杂而起到"软化"或"硬化"的作用。当Sb2O3掺杂量x≤0.005时,其压电系数d33随Sb2O3掺杂量的增加而增大,此时Sb2O3表现出了"软化"的特征;当Sb2O3掺杂量x>0.005时,d33降低,从而又表现出了"硬化"的特性;当Sb2O3掺杂≥0.010时,诱使陶瓷室温下反铁电微畴的形成,导致铁电性和压电性的骤减。

（1–x）[0.82Bi0.5Na0.5TiO3–0.18Bi0.5K0.5TiO3]–xSb2O3（BNKT–xSb） ceramics were prepared by a conventional solid-state solution technique.The influence of Sb2O3 additive on the microstructure and electrical properties of the BNKT–xSb ceramics was investigated.The BNKT–xSb ceramics appeared a pure perovskite structure in the whole range of Sb2O3（x0.020）.Sb2O3 might act as a ＂donor＂ or an ＂acceptor＂ in this piezoelectric ceramics due to its variable valences,which could change the electrical properties to ＂soft＂ or ＂hard＂.When x≤0.005,the piezoelectric coefficient（d33） of BNKT–xSb increased with the increase of Sb2O3 content,which is a characteristic of the ＂soft＂ doping.On the contrary,a ＂hard＂ property was induced when x0.005 at which d33 decreased again.The ferroelectric and piezoelectric properties of BNKT–xSb ceramics changed when x≥0.010,which could be correlated to the formation of anti-ferroelectric micro-domains at room temperature.