Magnetization Enhancement of Fe3O4 by Attaching onto Graphene Oxide: An Interfacial Effect

In this paper, we have reported about the enhancement of magnetization and blocking temperature of the Fe3O4-reduced graphene oxide (RGO) nanocomposite, which is formed by embedding Fe3O4 nanoparticles onto RGO sheets. We utilized powder X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy (EELS), energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques to investigate the crystallinity, morphology, phase, composition, purity, and evolution of oxidation states of nanosized Fe3O4 (S1) and Fe3O4-RGO nanocomposite (S2). EELS, Raman, and XPS all together indicate that GO is converted into RGO during the formation of the Fe3O4-RGO nanocomposite. Analysis of Fe 2p3/2 and Fe 2p1/2 peaks in the XPS spectrum of S1 and S2 reveals that Fe2+ ions are converted to Fe3+ ions during the formation of the Fe3O4-RGO nanocomposite, which has been proposed as the main reason for enhancement in magnetization. Enhancement of the blocking temperature of S2 with respect to S1 is due to the enhancement in the size of the magnetic domain in S2.