Halloysite nanotubes coated with magnetic nanoparticles

Co nanoparticles were assembled on the surface of halloysite nanotubes (HNTs) to prepare one-dimensional magnetic Co-HNTs via electroless deposition. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDXS) and vibrating sample magnetometer (VSM). The cobalt nanoparticles of 3-7 nm in size were uniformly deposited on the surface of the nanotubes. The remanent magnetization (M-r), saturation magnetization (M-s) and coercivity (H-c) values of the Co-HNTs were 13.9 emu/g, 27.05 emu/g and 1659 O-e, respectively, larger than that of the pure Co nanoparticles (580.72 O-e). A mechanism of the deposition of the magnetic nanoparticles on the surface of the halloysite nanotubes is suggested. Co-HNTs showed an interesting potential in the field of magnetic devices. (C) 2011 Elsevier B.V. All rights reserved.