Bakken Kristine, Pedersen Viviann H, Blichfeld Anders B, Nylund Inger-Emma, Tominaka Satoshi, Ohara Koji, Grande Tor, Einarsrud Mari-Ann
Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Trondheim 7491, Norway.
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan.
ACS Omega. 2021 Mar 30;6(14):9567-9576. doi: 10.1021/acsomega.1c00089. eCollection 2021 Apr 13.
Carbonate formation is a prevailing challenge in synthesis of BaTiO, especially through wet chemical synthesis routes. In this work, we report the phase evolution during thermal annealing of an aqueous BaTiO precursor solution, with a particular focus on the structures and role of intermediate phases forming prior to BaTiO nucleation. infrared spectroscopy, X-ray total scattering, and transmission electron microscopy were used to reveal the decomposition, pyrolysis, and crystallization reactions occurring during thermal processing. Our results show that the intermediate phases consist of nanosized calcite-like BaCO and BaTiO phases and that the intimate mixing of these along with their metastability ensures complete decomposition to form BaTiO above 600 °C. We demonstrate that the stability of the intermediate phases is dependent on the processing atmosphere, where especially enhanced CO levels is detrimental for the formation of phase pure BaTiO.
在钛酸钡（BaTiO₃）的合成过程中，尤其是通过湿化学合成路线时，碳酸盐的形成是一个普遍存在的挑战。在这项工作中，我们报告了水性BaTiO₃前驱体溶液热退火过程中的相演变，特别关注BaTiO₃成核之前形成的中间相的结构和作用。利用红外光谱、X射线全散射和透射电子显微镜来揭示热处理过程中发生的分解、热解和结晶反应。我们的结果表明，中间相由纳米尺寸的方解石状碳酸钡（BaCO₃）和BaTiO₃相组成，并且它们的紧密混合及其亚稳性确保了在600℃以上完全分解形成BaTiO₃。我们证明中间相的稳定性取决于加工气氛，特别是增强的CO₂水平不利于形成纯相BaTiO₃。
