▎ 摘　　要

The Nd-La doped Sr2CuMgFe28O46 magnetic nanoparticles were successfully fabricated by a green sol gel method. Decorating the magnetic nanoparticles on reduced graphene oxide (RGO) sheets was performed via a facile green chemical reaction strategy, where the reduction of graphene oxide and connection of magnetic nanoparticles with RGO by dopamine, occurred simultaneously. The as-fabricated magnetic nanoparticles were characterized systematically through the use of an X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), fourier transform infrared spectroscopy (PT-IR), network analyzer, particle size analyzer (PSA) and a vibrating sampling magnetometer (VSM). The results revealed that the magnetic nanoparticles were spherical-shaped with hexagonal ferrite structure and a grain size of 10 to 98 nm, approximately. Characterization of RGO/Nd-La doped Sr2CuMgFe28O46 nanocomposite using FT-IR clearly demonstrates the successful covalent attachment of magnetic nanoparticles to RGO sheets. Magnetic measurement revealed that the saturation magnetization (M-s) and coercivity (H-c) of magnetic nanoparticles were 44.3 Am-2/Kg and 0.445 T, respectively. As expected, the magnetic response of the nanocomposite was dramatically reduced in comparison with that in magnetic nanoparticles. Microwave absorption of the nanocomposite was evidently enhanced compared to that of pure graphite and magnetic nanoparticles. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.