Experimental and simulation-based understanding of morphology controlled barium titanate nanoparticles under co-adsorption of surfactants

• Published in: CrystEngComm Vol. 19; no. 24; pp. 3288 - 3298
• Main Authors: Sun, Zhongyu, Zhang, Lei, Dang, Feng, Liu, Yao, Fei, Zhiying, Shao, Qian, Lin, Hong, Guo, Jiang, Xiang, Lichen, Yerra, Narendranath, Guo, Zhanhu
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Barium titanates; Dissolution; Frequency ranges; Hydrazines; Molecular dynamics; Morphology; Nanoparticles; Oleic acid
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/c7ce00279c

Well dispersed single-crystalline BaTiO 3 nanoparticles with controlled morphologies were synthesized using a thermohydrolysis route. The nanoparticles were tuned from spherical to cubic upon changing the NaOH concentration under a critical molar ratio of oleic acid to hydrazine. Density functional theory (DFT) and molecular dynamics (MD) calculations indicated that hydrazine molecules adsorbed preferably on the Ti position of the Ti-O terminated surface; meanwhile, oleic acid molecules tended to adsorb on the Ba position of the Ba-O terminated surface. The added hydrazine changed the formation mechanism of BaTiO 3 nanoparticles from an in situ growth to a dissolution-precipitation growth. Excellent dispersibility in aqueous solution was achieved for the BaTiO 3 nanoparticles under the assistance of hydrazine. Meanwhile, a high-quality self-assembled film with a stable dielectric constant of 30 in the frequency range from 0 Hz to 1 MHz was prepared using the well dispersed BaTiO 3 nanoparticles, providing a novel low-temperature route for the fabrication of perovskite films. Selective adsorption of surfactants was theoretically predicted on crystal faces to prepare well-dispersed nanoparticles for the self-assembly of a high-quality stable dielectric constant film.