Preparation and characterization of MnZn-ferrite nanoparticles using reverse micelles

Research on manganese zinc ferrites (MZFO) has undergone a renewal in recent years as advances in synthetic techniques promise smaller grain sizes and corresponding changes in material properties. Current techniques for nanoscale synthesis of ferrites, however, produce a broad distribution of particle sizes, thus limiting the density of compacted materials, and consequently altering coercivity [C. Rath , J. Appl. Phys. 91, 2211 (2002)]. To minimize porosity, bulk materials need to be pressed from uniform particles. Wet chemical synthesis performed in reverse micelles, in which pools of water are encased by surfactant molecules in an excess volume of oil, provides the greatest control over size and morphology. During synthesis, surfactant molecules keep particles separated and restrict particle growth. This affords greater control over the size and shape of the particles grown in the micelles and commonly results in highly uniform morphologies [J. P. Chen , J. Appl. Phys. 76, 6316 (1994); C. Liu , J. Phys. Chem. B. 104, 1141 (2000)]. As a first step, it is necessary to produce pure phase, nanosized ferrite particles, therefore in this study, analysis of the powder of a sample prepared by a reverse micelle technique is compared to a sample prepared by a traditional ceramic method. Future studies will focus on the porosity and subsequent material properties of compacted forms of the pure phase samples. (C) 2003 American Institute of Physics.