Jaita Pharatree, Watcharapasorn Anucha, Jiansirisomboon Sukanda
Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.
Nanoscale Res Lett. 2012 Jan 5;7(1):24. doi: 10.1186/1556-276X-7-24.
Lead-free piezoelectric compositions of the (1-x)Bi0.5(Na0.40K0.10)TiO3-x(Ba0.7Sr0.3)TiO3 system (when x = 0, 0.05, 0.10, 0.15, and 0.20) were fabricated using a solid-state mixed oxide method and sintered between 1,050°C and 1,175°C for 2 h. The effect of (Ba0.7Sr0.3)TiO3 [BST] content on phase, microstructure, and electrical properties was investigated. The optimum sintering temperature was 1,125°C at which all compositions had densities of at least 98% of their theoretical values. X-ray diffraction patterns that showed tetragonality were increased with the increasing BST. Scanning electron micrographs showed a slight reduction of grain size when BST was added. The addition of BST was also found to improve the dielectric and piezoelectric properties of the BNKT ceramic. A large room-temperature dielectric constant, εr (1,609), and piezoelectric coefficient, d33 (214 pC/N), were obtained at an optimal composition of x = 0.10.
采用固态混合氧化物法制备了(1 - x)Bi0.5(Na0.40K0.10)TiO3 - x(Ba0.7Sr0.3)TiO3体系（x = 0、0.05、0.10、0.15和0.20）的无铅压电组合物，并在1050°C至1175°C之间烧结2小时。研究了(Ba0.7Sr0.3)TiO3 [BST]含量对相、微观结构和电学性能的影响。最佳烧结温度为1125°C，此时所有组合物的密度至少为其理论值的98%。随着BST含量的增加，显示四方性的X射线衍射图谱增加。扫描电子显微镜照片显示，添加BST时晶粒尺寸略有减小。还发现添加BST可改善BNKT陶瓷的介电和压电性能。在x = 0.10的最佳组成下，获得了较大的室温介电常数εr（1609）和压电系数d33（214 pC/N）。
