Nonstoichiometric M-ferrite porous spheres: preparation, shape evolution and magnetic properties

We developed a simple one-pot solvothermal process to prepare porous M-ferrite (M=Ni, Zn, Co, Mn, Mg) magnetic spheres using different M2+ and Fe3+ with the introduction of dodecylamine. As-prepared ferrites were characterized in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and selective area electron diffraction (SAED). XRD and EDS results showed that M-ferrites were nonstoichiometric in nature. Monodispersed magnetic ferrite spheres had a size distribution of 100-500 nm with different composition of M2+. Morphology evolution of ferrites upon reaction time and different metal doping has been studied. Furthermore, magnetic properties of M-ferrite spheres could be tuned by changing substituted metal cations. The influence of calcination on the phase and magnetic property was also investigated. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.