新型无铅压电陶瓷BNKT-BiFeO_3的研究

采用传统陶瓷制备法制备了一种新型无铅压电陶瓷(1-x)Bi_(0.5)(Na_(0.82)K_(0.18))_(0.5)TiO_3-xBiFeO_3(BNKT-BFx).研究了Bi基铁电体BiFeO_3对BNKT-BFx陶瓷晶体结构、显微组织和压电性能的影响.结果表明,在所研究的组成范围内陶瓷材料均能形成纯钙钛矿固溶体,陶瓷的准同型相界位于x=0～0.05.BiFe_O3促进陶瓷致密化和晶粒生长,在准同型相界成分附近压电性能达到最大值:d_(33)=171 pC/N,k_p=0.366.

Study on New Lead-free Piezoelectric Ceramics of BNKT-BiFeO3

A new (Bi_(0.5)Na_(0.5))TiO_3-based lead-free piezoelectric ceramics,(1-x)Bi_(0.5)(Na_(0.82)K_(0.18))_(0.5)TiO_(3-x)BiFeO_3 (BNKT-BFx),was prepared by the conventional ceramic sintering technique.The effect of Bi-based ferroelectrics of BiFeO_3 on the crystal structure,microstructure and piezoelectric properties was investigated.X-ray diffraction patterns indicated that the ceramics studied can form pure perovskite structure.The morphotropic phase boundary (MPB) of the system between the rhombohedral and tetragonal located in the range of x=0～0.05.The density and grain size were increased by BiFeO_3 addition.The piezoelectric constant d_(33) and the electromechanical coupling factor k_p of the ceramics attain maximum values of 171 pC/N and 0.366 respectively at x=0.03.