Self-assembly of magnetite beads along multiwalled carbon nanotubes via a simple hydrothermal process

Fe3O4 beads, with average diameters of ca. 180 nm and narrow size distribution, were self-assembled along multiwalled carbon nanotube (MWCNT) and formed necklace-like nanostructures through a simple, effective and reproducible hydrothermal method. TEM, SEM, XRD and SAED were used to characterize the as-synthesized samples. Results indicate these Fe3O4 beads were constructed with tiny nanocrystallites through oriented aggregation on the surface of MWCNT template. Further investigation indicates that denseness, size and crystallinity of these beads can be altered by control the reaction parameters. Associating with high magnetic sensitivity of magnetite beads, this novel magnetite/MWCNT heterojunction has potential to be used as electronic nanodevice and may open a way for precise manipulation of MWCNT-based hybrid which could be used to form integrated nanoscale electronic systems. (c) 2007 Elsevier Ltd. All rights reserved.