用固相法制备了(Na0.8K0.2)0.5Bi0.5TiO3+xmol%SrCO3+xmol%MnCO3(0≤x≤1.25%)(简称NKBTSM)无铅压电陶瓷,用XRD、SEM、Agilent 4294A精密阻抗仪等对该体系陶瓷的结构与电性能进行表征。结果表明:所制备的NKBTSM陶瓷样品均为单一的钙钛矿结构。Sr和Mn的复合掺杂促进了晶粒的长大,并提高了致密度。与纯NKBT陶瓷相比,掺杂Sr和Mn能提高陶瓷的压电常数d33、机电耦合系数kp和机械品质因子Qm,降低陶瓷的介质损耗tanδ。该系陶瓷具有介电弛豫特性,弥散因子随x的增加先增大后减小。综合考虑:x=1.00%陶瓷的电学性能最佳:d33=152pC/N,Qm=195,kp=28.66%,εr=701,tanδ=2.84%。
The (Na_(0.8)K_(0.2))_0.5Bi_(0.5)TiO_3+xmol%SrCO3+xmol%MnCO3 (0 ~〈 x ~〈 1.25%) (abbreviated as NKBTSM) lead-free piezoelectric ceramics were fabricated by solid state reaction. The structure and electric properties of the NKBTSM ceramics were characterized by XRD, SEM and Agilent 4294A impedance analyzer. It is found that all the samples exhibit a pure perovskite phase. The grain size and density of those materials increase as the Sr and Mn content increasing. Compared with pure NKBT, the piezoelectric constant d33, electromechanical planar coupling factor kp and mechanical quality factor Qm increase, while dissipation factor tan 5 decreases after Sr and Mn are added. NKBTSM system shows relaxor characteristics. The dispersion factor value increases first and then decrease with the increase of x. Such system with the best comprehensive properties can be obtained at x=l.00%, d33, Qm, kp, ε and tan5 is 152pC/N, 195, 28.66%, 701 and 2.84%, respectively.