Na1/2Bi1/2TiO3-BaTiO3系陶瓷压电性?及弛豫相变研究

系统研究了（１－ｘ）Ｎａ１／２Ｂｉ１／２ＴｉＯ３－ｘＢａＴｉＯ３（ｘ＝０．０２、０．０４、０．０６、０．０８、０．１０）无铅压电陶瓷系统的相界、材料压电性能，弛豫特性及相变．这个系统的陶瓷材料具有Ｋｔ／Ｋｐ较大，频率常数比较高等特点．Ｘ－ｒａｙ衍射结构分析发现此系统的相界在０．０４＜ｘ＜０．０６之间；材料的一些主要性能在相界附近达到极值．利用介电系数－温度曲线，并结合热激电流曲线对此系统的弛豫性进行研究和分析；初步研究了各配方组成的铁电－顺电的相变过程，发现在一定的组成范围内，材料在由铁电相向顺电相的转变过程中经历了一个过渡相区．

Piezoelectric Property and Relaxation Phase Transition of Na1/2Bi1/2TiO3-BaTiO3 System

For (1-x)Na1/2Bi1/2TiO3-xBaTiO3(x=0.02, 0.04, 0.06, 0.08, 0.10) lead-free ceramic system the morphotropic boundary, piezoelectric property, relaxation property and phase transition were investigated. The piezoelectric ceramics of this system possess large ratios of Kt/Kp and high frequency constants. According to XRD patterns, the morphotropic boundary lies in the composition range of 0.04< x <0.06. The main physical properties of this system can reach extreme values near the morphotropic boundary. The relaxation property of this system was studied by using dielectric constant-temperature curves and thermally stimulated depolarization current (TSDC) curves. Phase transition from ferroelectric to paraelectric phase was also primarily discussed and it was found out that the ceramics within a composition range possess transitional phase region between ferroelectric phase and paraelectric phase.