Controlled synthesis and magnetic properties of monodisperse Ni1-xZnxFe2O4/MWCNT nanocomposites via microwave-assisted polyol process

Ni1-xZnxFe2O4/MWCNT nanocomposites (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1) with controllable composition have been successfully synthesized via microwave-assisted polyol process using triethylene glycol solution (TREG) as solvent. Experimental results demonstrated that monodisperse face-centered cubical Ni1-xZnxFe2O4 nanoparticles with average size (6 nm) had been attached on the MWCNTs. The composition of ferrite nanoparticles can be controlled through adjusting the atomic ratios of the nickel and zinc salts in the mixed nitrate solution. The magnetic properties of nanocomposites with different Zn contents were measured by vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of Ni1-xZnxFe2O4/MWCNT nanocomposites gradually increases when the x is less than 0.5 while decreases when the x is larger than 0.5. Ms reached maximum value when the x is 0.5. The coercivity (Hc) of nanocomposites is low at room temperature, which exhibits characteristic of superparamagnetic. (C) 2012 Published by Elsevier B. V.