NiO nanoflakes: Effect of anions on the structural, optical, morphological and magnetic properties

NiO nanoflakes and nanosheets are successfully synthesized with different anions via homogeneous precipitation method. The prepared samples are characterized by XRD, SEM, TEM-SAED, DRS, PL and VSM analysis. XRD pattern confirms the presence of cubic bunsenite phase with preferred orientation along (200) direction. SEM images exhibits the presence of nanoflakes, semi-spherical, flower-like and nanosheet shaped particles with an average size 34 nm. The estimated band gap energy and refractive index are found to be in the range 3.79-4.18 eV and 1.48-1.93 respectively. Blue emissions in PL spectrum with a strong band centered at 425 nm and green emission band at 537 nm confirmed presence of crystal defects in NiO lattice. VSM analysis reveals the presence of superparamagnetic and weak ferromagnetic behavior in the NiO nanoparticles. (C) 2017 Published by Elsevier B.V.