采用传统电子陶瓷工艺制备了(Pb1-xCax)1.05(Nb0.95Ti0.05)2O6(x=0、0.045、0.055、0.065)高温压电陶瓷,研究了Ca和Ti对陶瓷的显微组织、相结构、介电及压电性能的影响,得到了Ca取代量与(Pb1-xCax)1.05(Nb0.95Ti0.05)2O6陶瓷性能间的关系。X-射线衍射(XRD)分析表明,Ca和Ti的双位取代均形成正交铁电相,而相同方法制备纯的PbNb2O6,只能得到菱方非铁电相钨青铜结构,随着Ca的摩尔分数增加,晶胞体积减小。介电温谱测试表明该改性材料具有高居里温度(TC〉530℃)。当x(Ca)=0.055时,得到压电常数d33=86pC/N、平面机电耦合系数kp=0.32、机械品质因数Qm=31.9、TC=536℃的陶瓷样品,材料可在高温(500℃)环境下使用。
Piezoelectric ceramics (Pb1-xCax)1.05(Nb0.95Ti0.05)2O6 (x=0,0.045,0.055,0.065) were prepared using the standard electronic ceramics method.Influences of Ca and Ti on the microstructure,phase structure,dielectric and piezoelectric properties of the ceramics were investigated,gaining the relationship between Ca replacement amount and the performance of (Pb1-xCax)1.05(Nb0.95Ti0.05)2O6 piezoelectric ceramics.XRD analysis showed that the double-position replacement of Ca and Ti could form the orthorhombic ferroelectric phase,while the pure PbNb2O6 prepared by the same method was shown to be the rhombohedral tungsten bronze type structure.In addition,the cell volume reduces with the increase of Ca content x.The dielectric temperature spectrum showed that the modified material had high Curie temperature(TC〉530 ℃).When x(Ca) = 0.055,the piezoelectric constant (d33) and electromechanical coupling coefficient (kp) were excellent,and the values of d33,kp,Qm and TC have reached to 86 pC/N,0.32,31.9 and 536 ℃,respectively.The ceramic samples are suitable for the application at high temperatures(500 ℃)as piezoelectric transducers.