【摘要】 采用传统陶瓷的制备方法,制备出(1-x)Na0.44K0.06Bi0.5TiO3-xNaNbO3(x=0~0.10)的无铅压电陶瓷。X-射线衍射(XRD)分析表明,所研究的组成均形成纯钙钛矿(ABO3)型固溶体,其晶体结构则随NaNbO3含量的增加由三方转变为假立方结构,并最终转变为立方结构。陶瓷材料的介电常数-温度曲线显示该体系材料为弛豫型铁电体,随着NaNbO3的增加,材料的弛豫性增强;采用改进的居里-外斯定理可较好地描述材料的介电常数-温度关系。测试了不同组成陶瓷的压电性能,当NaNbO5含量为0.08 mol时,陶瓷的压电常数d33和平面机电耦合系数kp比基础组成略有下降,但其介电常数3Tε3/0ε和介质损耗tanδ则有较大程度的增加。更多还原

【Abstract】 The（1-x） Na_0.44K_0.06Bi_0.5TiO₃-x NaNbO₃（x = 0 0.10） lead-free piezoelectric ceramics were fabricated by conventional ceramics technique.The crystalline structure of all compositions is mono-perovskite phase ascertained by XRD.The crystalline symmetry varied from rhombohedral to pseudo-cubic,and then to cubic at x = 0.10.The dielectric constant as function of temperature showed that all specimens were relaxor ferroelectric,and the relaxation character increased with the amount of NaNbO₃.The relation between dielectric constant and temperature could be characterized well by modified Curie-Weiss law.When x = 0.08 mol,the piezoelectric properties indicated the piezoelectric constant d₃₃ and planar electromechanical coupling factor k_p decreased a little,while the dielectric constant ε^T₃₃/ε₀ and dielectric loss tan δ improved much more.更多还原