Microwave-assisted polyol synthesis and magnetic properties of monodisperse Ni 1-xZn xFe 2O 4/MWCNTs nanocomposites

Ni 1-xZn xFe 2O 4/MWCNTs nanocomposites(x=0.4, 0.5, 0.6) with controllable composition have been successfully fabricated via microwave-assisted polyol route using triethylene glycol solution (TREG) as solvent. The structure and morphology of the final products were characterized by XRD, SEM, TEM and EDX. The magnetic properties were measured by VSM. The influence of microwave power and microwave time on loading has also been investigated. The results show that the spinel Ni 1-xZn xFe 2O 4 nanoparticles with a face-centered cubic structure appear to be a monodisperse distribution on MWCNTs. The average sizes of the nanoparticles were about 6 nm. The magnetic properties of Ni 1-xZn xFe 2O 4/MWCNTs nanocomposites vary with ferrite composition. The saturation magnetization (M s) of Ni 1-xZn xFe 2O 4/MWCNTs nanocomposites increases firstly and then decrease with Zn content increasing. M s reaches a maximum value when x equals to 0.5. The nanocomposites exhibit low coercivity (H c) at room temperature, which can be a typical characteristic of superparamagnetic.