Synthesis, studies and growth mechanism of ferromagnetic NiFe2O4 nanosheet

Nickel ferrite (NiFe2O4) nanoparticles were prepared by a simple and cost-effective method using nickel nitrate, ferric nitrate, ethylene glycol and citric acid via polyvinylpyrrolidone (PVP) assisted sol–gel auto-combustion method. The structure, composition, morphology and magnetic properties of the gel precursor were characterised XRD confirmed the formation of single phase NiFe2O4 with space group Fd3 m and inverse spinel structure and the crystallite size was found to be 29 nm. The FT-IR showed absorption bands, which were assigned to the vibration of tetrahedral and octahedral complexes. The thermal decomposition of the gel precursors was investigated by TGA. HR-SEM and TEM images showed sheet-like nanostructure. The magnetic properties of these nanosheets were studied for the enlightening ferromagnetic behaviour at room temperature. The magnetic saturation (Ms = 41.70 emu g−1), remanent magnetisation (Mr = 7.57 emu g−1) and coercive force (Hc = 162.47 Oe), were determined.