Magnetic Properties Investigation of Superpararmagnetic Co0.5Zn0.5Fe2O4 Prepared at Room Temperature

Magnetic nanoparticles are of great technological importance because of their use in magnetic fluid, information storage system, medical diagnostics, etc [1]. Some of the novel properties in magnetic nanoparticles, such as superparamagnetism, quantum magnetic tunneling, and surface spin canting effect, have generated further interest in the study of nanoparticle spinels [2].Among spinel ferrites, cobalt ferrite, CoFe2O4 is especially interesting because of their high cubic magnetocrystalline anisotropy, high chemical stability, wear resistance and electrical insulation. Cobalt ferrites crystallize in an inverse spinel form [3]. According to their crystal structure, spinel-type ferrites have natural superlattice. They have tetrahedral A sites and octahedral B sites in AB2O4 crystal structure [4].Frenkel and Dorfman [5] were the first to predict that a particle of ferromagnetic material, below a critical particle size (<15 nm for the common materials), would consist of a single magnetic domain, i.e. a particle that is a state of uniform magnetization at any field. The magnetization behavior of these particles above a certain temperature, i.e. the blocking temperature, is identical to that of atomic paramagnets (superparamagnetism) except that an extremely large moment and thus, large susceptibilities are involved [5].Many methods have been developed to prepare nanocrystalline. Chemical precipitation and co-precipitation are the economical routes for the production of large quantities of nanosized ferrite particles [6].The purpose of this work is to prepare and characterize nanoparticles of cobalt-zinc ferrite (Co0.5Zn0.5Fe2O4) at room temperature by co-precipitation method without subsequent calcination and as well as to investigate their magnetic properties. Characterization techniques like elemental analysis by XRD, TEM, VSM, AC-suseptibility and FTIR have been utilized