Facile Preparation Approaches and Prospective Applications for Nanostructured Ferrites

Abstract

With the development of synthesis of nanomaterials, magnetic ferrites and the traditional magnetic materials can be prepared by new methods, including top-down and bottom-up approaches. Ferrites are economic magnetic materials and are also being developed for new applications. Recent work on facile preparations and prospective applications for nanostructured ferrites will be discussed. Soft and hard ferrites are generally produced by ceramic routes in industry, but in present work, wet-chemical synthesis routes are utilized. Lithium ferrites were doped with Zn and Mg using co-precipitation method. They have shown promise in absorbers and sensors. Cobalt ferrite nanocrystals were prepared by a simplified sol-gel method namely the WOWS (without water and surfactants) sol-gel method. Cobalt ferrites with adjustable electrical properties have been obtained by doping a small amount of RE elements. Structural analysis of the prepared samples was done by X-ray diffraction (XRD). Lattice parameters and crystallite sizes were determined by using XRD data. Spinel structure was observed for all the prepared samples but with different space groups. DC electrical resistivity was measured as a function of temperature, and activation energies were determined from the Arrhenius plots for all the samples and their comparative study was done. Resistivity of all the samples was decreased with increase in temperature which indicated their semiconductor-like behavior. Polaron hopping was the major conducting mechanism as activation energies for all the samples were above 0.4 eV. The studied materials can be utilized in advanced electronics industries.