Fabrication and characterization of uniform Fe3O4 octahedral micro-crystals

Uniform Fe3O4 octahedral microcrystals with perfect appearance have been successfully synthesized by a Triton X100-assisted polyol process. During the polyols process for the preparation of Fe3O4 octahedra. the introduction of Triton X100 decreases significantly the needed concentration of NaOH. The results show that Fe3O4 octahedra are composed of eight triangular sheets, which are equilateral triangles. The edge size of Fe3O4 octahedron is about 4 mu m. The magnetic properties of Fe3O4 octahedral particles were evaluated on a SQUID magnetometer at room temperature. The value of saturation magnetization for Fe3O4 octahedra is 90 emu/g, which is close to the value of bulk magnetite. The remnant magnetization and coercive force of Fe3O4 octahedra are considerably low, which are rare for the Fe3O4 particles with the size scale of micrometers. The Fe3O4 octahedral microcrystals show high saturation magnetizations and very low coercivities. (c) 2008 Elsevier B.V. All rights reserved.