Synthesis of Fe3O4 hollow microsphere chains and their magnetic properties

Fe3O4 hollow microsphere chains with lengths of 8-11 mu m have been solvothermally synthesized in the mixed solution of glycerol and water with 1 M NaOH. The hollow microspheres have diameters in the range 0.7-1 mu m, and the thickness of the shells is 150-300 nm. The shell of the hollow microspheres is constructed by octahedrons of 100-170 nm. However, when the concentration of NaOH is adjusted to 3 M, the octahedron chains with lengths of 30-50 mu m can be obtained. The magnetic saturation values of hollow microsphere chains and octahedron chains are 88.1 and 102.4 emu/g at room temperature, respectively. (C) 2009 Elsevier Ltd. All rights reserved.