水热合成Ba（ZrxTi1-x）O3的介电性能研究

在140℃加热14h的水热方法制备出Ba（ZrxTi1-x）O3（x=0,0.1％,0.2％,0.5％）粉体。研究了1200℃到1280℃的烧结效果。XRD物相分析证明其结构为单一钙钛矿相,在水热法合成过程中,引入Na^＋离子,使晶格半径减小。SEM结果显示,在1250℃烧结得到的陶瓷晶粒生长较好,结构致密,晶粒分布均匀。与固相反应法相比,水热法能够有效地降低烧结温度,合成的陶瓷密度可达92.4％。介电测量表明,作为矿化剂的Na^＋部分取代Ba^2＋,会导致Ba（ZrxTi1-x）O3样品的介电峰明显宽化。实验观察到样品在40℃时出现了明显的损耗峰,可能是钠离子替代钡离子并产生氧空位所致。介电常数随Zr掺杂量的增多呈上升趋势,居里点温度随Zr掺杂量的增多向低温方向偏移。

Research on dielectric properties of Ba(Zr_xTi_(1-x))O_3 prepared by hydrothermal method

The Ba（ZrxTi1-x）O3（x= 0, 0.1%, 0.2%, 0.5%） powers were prepared by the hydrothermal on the condition of 140℃ in 14 h. The dried powers were pressed into pellets and sintered for 2 h at temperatures ranging from 1200℃ to 1280℃. XRD investigation had confirmed that the powders had the crystalline of the pure perovskite structure. The results of SEM showed that the Ba（ZrxTi1-x）O3 ceramic sintering at 1250℃ was dense and had homogeneous distribution of grain size. Compared with experimental result of the solid reaction, the hydrothemal synthesis could decrease sintering temperature effectively,and the density of the ceramic was up to 92.4%. Because of the introducing of mineralizer Na^＋ to substitute for Ba^2＋, the dielecrric peak of Ba（ZrxTi1-x）O3 sample appeared obrious relaxation phenomena. The dielectric loss peak appeared at 40℃ for four different samples. The reason probably was oxygen vacancies produced by the introduction of sodium ions.