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Abstract: Fe3O4/CuPc hybrid material, where the CuPc not only interlinked but also be embedded within the Fe3O4 microspheres, was synthesized via solvothermal method. The electromagnetic properties of the sample showed cooperative nonlinear dielectric/magnetic resonance in X-band and Ku-band. The proposed equivalent filter circuit model well explained the dual nonlinear dielectric resonances. The magnetic resonances were proposed to be generated from the natural resonance of the Fe3O4 and heterogeneous interfaces in/between microspheres severally. The microwave absorption of the sample obtained two optimal nesting peaks of −35 and −33dB at 12.6 and 15.8GHz with thickness of 2.6 and 1.8mm respectively. [Copyright &y& Elsevier]

Abstract: Fe-phthalocyanine/Fe3O4 hybrid microspheres were synthesized from bis-phthalonitrile and FeCl3·6H2O through a simple and effective solvent-thermal route. The hybrids were monodispersed solid microspheres with diameter of ~400nm. The ferromagnetic signature emerged with the saturated magnetization of ~55.7emug−1, and the coercive force of ~93.7Oe at 300k. The addition of bis-phthalonitrile oligomer brought Fe3O4 nanoparticles novel dielectric property: a new dielectric loss peak appeared at ~8GHz. Considering the microwave magnetic loss properties, two microwave magnetic loss peaks were presented at ~1.5GHz and ~10GHz, the former peak was attributed to the natural properties of the Fe3O4, and the latter originated from the interface effects between the bis-phthalonitrile oligomer and Fe3O4. [ABSTRACT FROM AUTHOR]

Abstract: Magnetite nanoparticles are found to assemble into monodisperse Fe3O4 microspheres with diameters ∼300nm and open pores on the shells in ethylene glycol (EG) in the presence of polyethylene 2000 (PEG 2000) and a small quantity of polyethyleneimine (PEI). The hysteresis loops of the magnetic microspheres are measured by a vibrating sample magnetometer (VSM), the ferromagnetic signature emerged with the saturated magnetization of ∼80.0emug−1, and the coercive force of ∼208.7Oe. The synthesized hierarchical microspheres exhibit two microwave magnetic loss peaks: one appears at 4.0–5.0GHz, the other appears around 16.0–17.0GHz. The latter peak is attributed to the effect of the morphology of the hierarchical structure. Modern analysis methods SEM, TEM, XRD etc., are employed to figure the detailed structure information of the magnetic hollow spheres. [Copyright &y& Elsevier]

Abstract: In this work, the microwave electromagnetic performances of ferrocenyl organic magnetic material as being influenced by a rare earth metallic oxide Eu2O3 doping have been investigated. The dopant concentration was varied between 1 and 4wt.%. The results obtained revealed that the electromagnetic parameters including complex permittivity and permeability at high frequencies changes with the vibration of the dopant concentration of Eu2O3. Furthermore, the microwave absorbing capacity at high frequencies was increased by increasing the dopant concentration of Eu2O3. The maximum microwave absorption of −15.8dB at Ku-band, which was much bigger than that of pure ferrocenyl organic magnetic material, achieved from the doping concentration of 4% for Eu2O3. [Copyright &y& Elsevier]

Abstract: A novel sandwich-like graphene nanosheets (GNs)/Fe3O4 hybrid material was synthesized through a facile one-pot solvothermal method using FeCl3 as iron source, ethylene glycol as the reducing agent and graphene nanosheets as templates. The Fe3O4 nanoparticles, with the average diameters of ca. 40nm, were self-assembled on the graphene nanosheets through electrostatic attraction and formed sandwich-like nanostructure. The ferromagnetic signature emerged with the saturated magnetization of ~72.3emu g−1, and the coercive force of ~196.1Oe at 300K. The magnetic loss was caused mainly by natural resonance which is in agreement with the Kittel equation. The novel electromagnetic hybrid material is believed to have potential applications in the microwave absorbing performances. [Copyright &y& Elsevier]