Synthesis of monodisperse Fe@SiO2 core-shell nanocapsules and investigation of their magnetic behaviour

• Published in: Micro & nano letters 2019-08, Vol.14 (9), p.976-979
• Main Authors: Zeng, Wen, Yang, Qiqi, Shao, Bin, Guo, Donglin, Li, Chunhong, Ma, Yilong, Yin, Xueguo, Zhao, Sibo, Li, Kejian
• Format: Article
• Language: English
• Subjects: Chemical synthesis; coercive force; Coercivity; core‐shell nanostructures; Electron microscopes; Electron microscopy; Fe‐SiO2; Heat treatment; hydrothermal reaction; Hydrothermal reactions; iron; liquid phase deposition; magnetic particles; Magnetic properties; magnetic property measurement system; mean particle size; Microscopy; monodisperse core‐shell nanocapsules; nanofabrication; nanomagnetics; nanoparticles; nanostructures; particle length; particle size; reaction temperature; saturation magnetisation; scanning electron microscopy; silica thickness; silicon compounds; Silicon dioxide; size 10 nm to 20 nm; size 25.0 nm to 35.0 nm; TEOS; Tetraethyl orthosilicate; Thickness; transmission electron microscopy; X‐ray diffraction
• ISSN: 1750-0443; 1750-0443
• DOI: 10.1049/mnl.2019.0063

The monodisperse Fe@SiO2 core-shell nanocapsules were synthesised via hydrothermal reaction followed with heat treatment. Nanostructures were characterised by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The magnetic properties of Fe@SiO2 nanocapsules were evaluated with magnetic property measurement system. The results show that Fe@SiO2 core-shell nanocapsules are highly monodispersed. The silica thickness of Fe@SiO2 nanocapsules increased from 10–20 to 25–35 nm with increasing tetraethyl orthosilicate (TEOS) amount. In the Fe@SiO2 nanocapsules prepared with 900 μl TEOS, as the reaction temperature increases, the mean particle size of Fe@SiO2 nanocapsules increases from 328 to 546 nm. It is remarkable that the saturation magnetisation of Fe@SiO2 nanocapsules decreases with increasing silica thickness. However, the coercivity of nanocapsules has less influence with the variation of silica thickness and particles’ length.