Nanocrystalline BaTiO_3 from freeze-dried nitrate solutions
Nanocrystalline BaTiO_3 from freeze-dried nitrate solutions
复制标题
冷冻干燥硝酸盐溶液中的纳米晶 BaTiO_3
DOI：
10.1557/jmr.1996.0154
复制
发表时间：
1996
影响因子：
2.7
通讯作者：
N. Coppa
中科院分区：
文献类型：
--
作者：
J. Mchale;P. McIntyre;K. Sickafus;N. Coppa
本文报道了一种全硝酸盐溶液基制备BaTiO_3的方法。将硝酸钡和硝酸钛溶液快速冷冻，然后对溶剂进行低温亚限制，得到冷冻干燥的硝酸前驱体，该前驱体经热处理生产BaTiO_3。XRD结果表明，在≥600℃的温度下，10 min可形成相纯纳米晶BaTiO_3。透射电镜显示，该材料为均匀的纳米晶（10-15 nm）。这些小颗粒所固有的高表面体积比在室温下稳定了BaTiO_3的立方相。制备的BaTiO_3的平均粒径与煅烧温度高度相关，与退火时间仅轻微相关。这一结果为合理选择煅烧温度来选择产品粒度提供了一种方法。讨论了冻干前驱体制备、前驱体热加工、产物形成和产物形态的实验细节。
An aqueous, all nitrate, solution-based preparation of BaTiO_3 is reported here. Rapid freezing of a barium and titanyl nitrate solution, followed by low temperature sublimitation of the solvent, yielded a freeze-dried nitrate precursor which was thermally processed to produce BaTiO_3. XRD revealed that 10 min at temperatures ≧600 °C resulted in the formation of phase pure nanocrystalline BaTiO_3. TEM revealed that the material was uniform and nanocrystalline (10–15 nm). The high surface to volume ratio inherent in these small particles stabilized the cubic phase of BaTiO_3 at room temperature. It was also found that the average particle size of the BaTiO_3 produced was highly dependent upon calcination temperature and only slightly dependent upon annealing time. This result suggests a means of selection of particle size of the product through judicious choice of calcination temperature. The experimental details of the freeze-dried precursor preparation, thermal processing of the precursor, product formation, and product morphology are discussed.