Wet Chemical Synthesis of High Aspect Ratio Magnetite Rods
Seville, J. P .K.
Magnetite with an aspect ratio of 10:1 was prepared by a seeding growth approach with a 0.35 T magnetic field applied. Studies show that magnetic field induced self-assembly of 50 nm diameter spherical particles, leading to the formation of a chain-like structure in alkaline media or a rod-like structure in acidic media. The addition of a small amount of seeds increases the yield of rod-like magnetite particles. The seeds are prepared by aging ferrous and ferric solution with sodium hydroxide as a precipitator. The aspect ratio of the rod increases with a decrease ratio of seed to iron salt. Seeds accelerate the initial reaction. A dependence of the morphology on the size of the seed is observed. Magnetic measurements reveal that magnetite rods are ferromagnetic with a saturation magnetization of 75.7 emu/g and coercivity of 386 Oe. Enhanced coercivity compared to without seeding is explained in terms of an increase of shape anisotropy.
X. Yang et al., "Wet Chemical Synthesis of High Aspect Ratio Magnetite Rods," Powder Technology, Elsevier, Oct 2011.
The definitive version is available at http://dx.doi.org/10.1016/j.powtec.2011.06.029
Materials Science and Engineering
Keywords and Phrases
Magnetite; Magnetic Fields; Seed; Rod; High Aspect Ratio
Article - Journal
© 2011 Elsevier, All rights reserved.