Nickel-Iron Spinel/Reduced Graphene Oxide Nanocomposites: Structural and Mossbauer Studies

Ultrafine nickel ferrite and nickel ferrite/ reduced graphene oxide (rGO) nanocomposite have been synthesized by hydrothermal method. Structural and magnetic properties of the obtained materials have been studied. XRD studies revealed that the joint hydrothermal synthesis of nickel ferrite and graphene oxide reduction leads to decreasing of ferrite particles to 8-9 nm. Normalized pair distance distribution functions and the most probable particle sizes were studied by SAXS method. The distribution of Fe ³⁺ and Ni ²⁺ cations between tetrahedral and octahedral sublattices was analyzed and transitions magnetic ordered state - spin glass like state - superparamagnetic state for ultrafine nickel ferrite were observed by Mossbauer spectroscopy.