Synthesis of Nickel-zinc Ferrite Nanoparticles in Polyols : Morphological and Magnetic Studies

Nickel–zinc ferrites are some of the most interesting soft magnetic materials. They have been extensively used in a number of electronic devices because of their low magnetic coercivity, low eddy current related to their high electrical resistivity, and they are especially suitable for high–frequency applications (large permeability). New low-temperature synthesis methods have been developed to obtain these materials; for example, reverse micelle technique [1], hydrothermal technique [2], citrate precursor method [3]. These methods do not allow simultaneous control of the morphology and the crystalline quality of the particles. A new chimie douce route was developed in our laboratory: forced hydrolysis of metallic salts dissolved and heated in a polyol. Polyols are crystal growth media of particular interest for the synthesis of fine particles with a narrow size distribution and high crystallinity [4-7].