Comparison of different methodologies for obtaining nickel nanoferrites

©2014 Elsevier B.V. All rights reserved. This investigation has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through MAT2012-37109-C02-01, MAT2012-37109-C02-02 and the CONSOLIDER CSD-00023 and ENE2010-21198-C04-04 Project. OBM thanks the financial support from the “Ramón y Cajal Program” of the MINECO.Nickel nanoferrites were obtained by means of four different synthetic wet-routes: co-precipitation (CP), sonochemistry (SC), sonoelectrochemistry (SE) and electrochemistry (E). The influence of the synthesis method on the structural and magnetic properties of nickel ferrite nanoparticles is studied. Although similar experimental conditions such as temperature, pH and time of synthesis were used, a strong dependence of composition and microstructure on the synthesis procedure is found, as electron microscopy, X-ray diffraction and Mössbauer spectroscopy studies reveal. Whereas by means of the CP and SC methods particles of a small size around 5–10 nm, respectively, and composed by different phases are obtained, the electrochemical routes (E and SE) allow obtaining monodisperse nanoparticles, with sizes ranging from 30 to 40 nm, and very close to stoichiometry. Magnetic characterization evidences a superparamagnetic behavior for samples obtained by CP and SC methods, whereas the electrochemical route leads to ferromagnetic ferrite nanoparticles.Depto. de Física de MaterialesFac. de Ciencias FísicasTRUEMinisterio de Economía y Competitividad (MINECO)CONSOLIDER Project"Ramon y Cajal Program" of the MINECOpu