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以Na2O5作为起始物,通过热碱反应与钽离子反应,通过浓度控制,清除钠离子工艺后,得到优质Na2O5.nH2O胶体;然后与Ba,Mg醋酸盐计量混合得到凝胶,经820℃,1h热处理后,制得BMT纳米粉末,进一步烧结后得到BMN纳米陶瓷,其相致密度达到98.2%,微波介电性能Q=10397(频率1.45GHz)。运用量子化学SCF-Xα-SW法对Ba(B′1/3B′′2/3)O3复杂钙钛矿结构进行电子结构分析,计算表明离子结合强度是Ba(Mg1/3Nb2/3)O3和BaTiO3结构稳定的关键参数,BMN中B位氧离子和阳离子的结合强度远高于BaTiO3,而且BMN的非平衡力导致B位离子在某一定方向有序化排列,这种有序结构导致A(B′,B′′)O3材料比ABO3材料更具优良的介电性能,并得到实验验证。因此有助于高品质因数微波介质陶瓷的设计和制备。
Take Na2O5 as a starting material, react with tantalum ions by hot alkali reaction, and get sodium colloids of good quality after sodium ion concentration control through concentration control; and then measure and mix with Ba and Mg acetate to obtain gel, After 1h heat treatment, BMT nanometer powder was obtained. After further sintering, the BMN nanocrystalline ceramic was obtained. The phase density reached 98.2% and the microwave dielectric property Q = 10397 (frequency 1.45GHz). The electron structure of Ba (B’1 / 3B’’2 / 3) O3 complex perovskite structure was analyzed by quantum chemical method SCF-Xα-SW. The results show that the ionic bond strength is Ba (Mg1 / 3Nb2 / 3) BaTiO3 structural stability of the key parameters, BMNO B ion and cation binding strength is much higher than BaTiO3, and BMN non-equilibrium force leads to B-site ions in a certain direction of ordering, this ordered structure leads to A ( B ’, B ") O3 materials have better dielectric properties than ABO3 materials and have been experimentally verified. Therefore contributing to the design and preparation of high quality factor microwave dielectric ceramics.