Processing and dielectric properties of the mixed-layer bismuth titanate niobate Bi7Ti4NbO21 by the metal-organic precursor synthesis method
Processing and dielectric properties of the mixed-layer bismuth titanate niobate Bi7Ti4NbO21 by the metal-organic precursor synthesis method
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DOI：
10.1016/s0955-2219(00)00161-8
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发表时间：
2001
影响因子：
5.7
通讯作者：
P. Durán;F. Capel;C. Moure;M. Villegas;J. Fernández;J. Tartaj;A. Caballero
中科院分区：
文献类型：
--
作者：
P. Durán;F. Capel;C. Moure;M. Villegas;J. Fernández;J. Tartaj;A. Caballero
采用基于Pechini型反应路线的金属-柠檬酸络合物法，在400-500°C温度下制备了均匀的Bi_7 Ti_4 Nb_（21）单相纳米陶瓷粉末。通过TG/DTA、XRD、拉曼光谱和SEM研究了聚合树脂的热分解/氧化过程，得到了结构清晰的正交晶系Bi 7 Ti4 NbO 21化合物，其晶格参数为a=0.544，B=0.540，c=2.905 ± 0.0005 nm。反应形成通过中间二元相进行，其化学计量接近于Bi 20 TiO 32，其在300和375°C之间形成。金属-有机前驱体合成方法允许控制Bi/Ti/Nb化学计量比，从而在比常规路线中通常所需的温度低得多的温度下快速形成纳米尺寸的钛酸铋钛酸盐（Bi 7 Ti4 NbO 21）陶瓷粉末。在1100-1130°C的温度范围内烧结所制备的陶瓷粉末导致接近全密度的样品。混合层结构的Bi 7 Ti4 NbO 21陶瓷在约650和850 ± 5°C下表现出两个相变，压电模量d33高达20×10− 12 C/N。
The preparation of homogeneous Bi7Ti4NbO21single phase nanosized ceramic powders at temperatures as low as 400–500°C using a metal-citrate complexes method, based on the Pechini-type reaction route, is described. The thermal decomposition/oxidation of the polymerized resin, as investigated by TG/DTA, XRD, Raman spectroscopy and SEM, led to the formation of a well defined orthorhombic Bi7Ti4NbO21compound with lattice parameters a=0.544, b=0.540 and c=2.905 ± 0.0005 nm. Reaction formation takes place through an intermediate binary phase with a stoichiometry close to Bi20TiO32which forms between 300 and 375°C. The metal-organic precursor synthesis method, allows the control of the Bi/Ti/Nb stoichiometric ratio leading to the rapid formation of the nanosized bismuth titanate niobate, Bi7Ti4NbO21, ceramic powders, at temperatures much lower than usually needed in the conventional route. Sintering of the as-prepared ceramic powders led to near full density samples in the temperature range 1100–1130°C. The mixed-layer structure Bi7Ti4NbO21ceramics showed two phase transitions at about 650 and 850 ± 5°C, and a piezoelectric modulus, d33, as high as 20×10−12C/N.