Co_2O_3掺杂0.828(Na,Bi)_(0.5)TiO_3-0.06(K,Bi)_(0.5)TiO_3-0.021BaTiO_3-0.091SrTiO_3无铅压电陶瓷结构与性能的研究

Structure and Electrical Properties of Co_2O_3-Doped0.828(Na,Bi)_(0.5)TiO_3-0.06(K,Bi)_(0.5)TiO_3-0.021BaTiO_3-0.091SrTiO_3 Lead- free Piezoceramics

采用固相法制备了(1-x){0.828(Na,Bi)0.5TiO3-0.06(K,Bi)0.5TiO3-0.021BaTiO3-0.091SrTiO3}-xCo2O3(简写为(1-x)NKBST-xCo,x为摩尔百分数)无铅压电陶瓷,研究了不同掺杂量的Co2O3对体系相结构与电性能的影响,XRD结果表明所有陶瓷样品均形成单一的钙钛矿固溶体结构,SEM结果表明少量Co的引入有利于晶粒生长,介电温谱表明Co的引入使得样品在Tm附近频率色散更加明显。室温下电性能表明:适量Co掺杂能够提高体系陶瓷的机械品质因子Qm,降低介质损耗tanδ,同时压电性能有所提高。当x=0.50mol%时,性能最佳:压电常数d33=226 pC/N,机械品质因子Qm=126,介质损耗tanδ=4.68%,平面机电耦合系数kp=33.4%。

Lead-free piezoelectric ceramics（1-x）（0.828（Na, Bi）0.5 TiO3-0.06（K, Bi）0.5TiO3- 0.021BaTiO3- 0.091SrTiO3）- xCo2O3（x - mol%）were prepared by the solid state route. Effects of the amount of Co2O3 on the electrical properties and phase transition were studied. The results of X- ray diffraction revealed that all the ceramic samples were pure perovskite phase; SEM indicated that the suitable Co2O3 addition was beneficial to the growing of grain size. The temperature dependence of dielectric constant showed that the frequency dispersion was more obvious at the temperature near the Tm. The test results of electrical properties indicated that the addition of Co enhanced the mechanical quality factor Qm, reduced the dissipation factor tanδ, and meanwhile increased the piezoelectric property. The best comprehensive properties of such system can be obtained at x = 0.50%： d33, Qm, tanδ, and kp were 226, 126, 4.68% and 33.4% respectively.