A facile synthesis of superparamagnetic hybrid hollow nanospheres based on monodisperse nickel-zinc ferrite/polyethylene glycol and their electromagnetic, microwave absorbing properties

摘要

Ni_(0.3)Zn_(0.5)Fe_2O_4/polyethylene glycol (PEG) hybrid hollow nanospheres have been successfully prepared using a facile synthesis method. Their shape, size and structure have been characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The determination from inductively coupled plasma (ICP) indicates that the atomic ratio of Ni/Zn/Fe is 3:5:20, the results from fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA) show that the PEG is also contained by the nanospheres, and thus an expression of Nio.3Zno.5Fe_2O_4/PEG is presented. A formation mechanism is suggested according to FTIR, XRD, TGA, TEM and selected area electron diffraction (SAED) with different reaction time: 4, 6, 8, 10, and 12 h. The magnetic measurement of the Ni_(0.3)Zn_(0.5)Fe_2O_4/PEG nanospheres reveals that the saturation magnetization is 86.26 emu g~(-1). The sample of 35% volume fraction (Ni_(0.3)Zn_(0.5)Fe_2O_4/ PEG/paraffin containing Ni_(0.3)Zn_(0.5)Fe_2O_4/PEG nanospheres) exhibits a minimum reflection loss (RL) of -50.15 dB at about 8.8 GHz in the range of 2-18 GHz. The Ni_(0.3)Zn_(0.5)Fe_2O_4/PEG nanospheres show unique morphology, favorable magnetism, as well as excellent microwave absorbing properties.