(1-x)BaTiO3-xAg0.9Li0.1NbO3系无铅压电陶瓷的相结构和电性能研究

Phase structure and electrical properties of (1-x)BaTiO_(3-x)Ag_(0.9)Li_(0.1)NbO_3 lead-free piezoelectric ceramics

采用传统陶瓷工艺制备了（1-x）BaTiO3-xAg0.9Li0.1NbO3（BT-xALN,0.005≤x≤0.04）系陶瓷,研究了ALN含量的变化对BT-xALN系陶瓷的显微结构、相结构和电性能的影响。结果表明,ALN的引入使陶瓷的晶粒尺寸有所减小。当x≤0.02时,BT-xALN陶瓷均形成了纯的钙钛矿相,表明ALN与BT形成了固溶体;当x=0.01~0.02时,陶瓷存在四方-伪立方相界。陶瓷的压电常数d33和介电常数εr随x增加均先增大后减小。d33在x=0.0075时达到最大值115pC/N,εr在x=0.025时达到最大值3 880;但剩余极化强度Pr随x增加逐渐降低。此外,掺入ALN后陶瓷的居里温度有所降低。

Lead-free piezoelectric ceramics（1-x）BaTiO_（3-x）Ag_（0.9）Li_（0.1）NbO_3（BT-xALN,0.005≤x ≤0.04）were prepared by the conventional solid state reaction.The influence of the ALN content on the microstructure,phase structure,and electrical properties of the BT-xALN ceramics were investigated.The grain size of the BT-xALN ceramics decreases with increasing x.The ceramics show pure perovskite structure for x≤0.02,suggesting that ALN has diffused into BT lattice to form solid solution.Two-phase coexistance between tetragonal and pseudo-cubic phases was found for x=0.01-0.02.As xincreases,both d33andεrincrease initially and then decrease with increasing x.For x=0.0075,the piezoelectric constant of the sample exhibits the maximum,d33 about 115pC/N.The dielectric constant（εr）shows the maximum value（about 3 880）for x=0.025.The remanent polarization（Pr）reduces slightly with increasing x.Moreover,the Curie temperature of the ceramics decreases with the addition of ALN.