Effects on direct synthesis of large scale mono-disperse Ni0.5Zn0.5Fe2O4 nanosized particles

Mono-disperse Ni0.5Zn0.5Fe2O4 spinel ferrite particles have been synthesized directly via the hydrothermal method using sodium dodecyl sulfate (SDS) as surfactant. Particle size could be varied from 6 to 19 nm by changing the experiment parameters. X-ray diffraction, high resolution TEM images confirmed the high crystallinity of ferrite nanocrystals. The effects of precursor suspension pH value, reaction temperature and surfactant (SDS) concentration on phase purity, particle size and dispersed property were discussed. The results indicated that mono-disperse Ni0.5Zn0.5Fe2O4 spinel ferrite nanoparticle had been obtained at pH value range (8-9), reaction temperature (90 degrees C) and moderate SDS concentration (>0.2 mM). The magnetic measurement shows that as prepared Ni0.5Zn0.5Fe2O4 nanoparticle possesses good super-paramagnetic behavior. We also put forward a primary experimental model to shed light on the controllability of the monodispersity of the nanosized particles. (C) 2007 Elsevier B.V. All rights reserved.