Synthesis, studies and growth mechanism of ferromagnetic NiFe2O4 nanosheet

• Published in: Applied surface science 2012-06, Vol.258 (17), p.6648-6652
• Main Authors: Sivakumar, P., Ramesh, R., Ramanand, A., Ponnusamy, S., Muthamizhchelvan, C.
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Nanostructure; NiFe2O4; Polymer; VSM
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.03.099

The morphology of the as-prepared sample is determined by HR-SEM, TEM and HRTEM. The morphology of the as prepared NiFe2O4 is sheet-like structure. HR-TEM shows clear lattice fringes of each nanoparticle. This is interpreted as oriented attachment and sample as sheet-like morphology. From the HR-TEM observations of single sheet-like nanostructures, and the fringe spacing is measured to be 0.291nm and 0.0.248nm, which confirms that the nanosheet is single crystal with lattice fringes being (220) and (311) planes. [Display omitted] ► Single-phase NiFe2O4 powders have been synthesised by a wet chemical route. ► XRD, FTIR, TGA, HR-SEM, TEM, HR-TEM and VSM study. ► The structural and magnetic properties of NiFe2O4 nanosheet. ► PVP plays an important role for the formation of the sheet-like nanostructure. ► Both TEM and HR-SEM image for NiFe2O4 nanocomposite shows the sheet-like nanostructure. 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 Fd3m and inverse spinel structure and the crystallite size was found to be 29nm. 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=41.70emug−1), remanent magnetisation (Mr=7.57emug−1) and coercive force (Hc=162.47Oe), were determined.