Abstract

Magnetic nanoparticles with high surface area, size-dependent superparamagnetic behaviour such as precision, tunability, and easy surface modification have become good materials for biomedical applications. Based on the synthesis method, nanoparticles can be engineered and manipulated with other organic or inorganic functional compounds to form multimodal nanocomposites useful in the ragnosis. Accordingly, the nanocomposites of Ni_xCo_x-1O/CoC₂O₄ were fabricated by a single molecular metal organic (oxalate) precursor from carambola fruit juice and the corresponding metal chlorides. The solid metal oxalate precursors obtained from precipitation decomposed at 325 °C to the corresponding metal oxides/oxalate. The PXRD and EDS mapping images revealed NixCo1-xO and CoC₂O₄. Nanoparticles coexisted in the composite while FTIR spectrum revealed the formation of cobalt oxalate metal organic framework without any surface adsorbed impurities. The Face cantered cubic phases of CoO with the particle size ranging from 9.0-15.0nm and CoC₂O₄ were assigned by the X-ray diffraction analysis. Nano tubes and cubic nano particle morphologies were identified from the Scanning Electron Microscopy (SEM) images and the variation in morphology and particle size was attributed to the presence of the nickel ion and the change in the concentration of the impurity ions. The magnetic properties exhibited by the synthesized Magnetic NixCo1-xO/Co₃O₄ Nanocomposites suggest that the as-synthesized nanocomposites have potential applications in negative contrast enhancing agents for Magnetic Resonance Imaging (MRI).

Keywords:Cobalt (II) oxide composite; Synthesis; Morphology; Particle size; Magnetism