چکیده (انگلیسی):

Precursors of nickel oxide (NiO) nanoparticles were synthesized through a
simple chemical precipitation method by changing the oxide source used for the
synthesis. The synthesized precursors were subjected to thermo gravimetric
analysis (TGA) to determine the temperature at which the precursors decompose
into nickel oxide. The obtained results of TGA suggest that precursor NiO
prepared using sodium hydroxide (NaOH) showed NiO formation at 600 °C,
whereas, when oxalic acid was used as oxide source the formation of NiO took
place at 400 °C. After calcinations of the precursors at respective temperatures,
NiO nanocrystals have been harvested. The synthesized NiO powders were
characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy
(FT-IR), photoluminescence (PL) spectroscopy, field emission scanning
electron microscopy (FE-SEM), energy dispersive x-ray analysis (EDX), and
vibrating sample magnetometer (VSM) analysis. An FE-TEM image of NiO
prepared using oxalic acid showed spherical and elliptical particles with sizes in
the range of 15 nm. The Williamson–Hall (W–H) plots were drawn for the
annealed products to study their lattice strain and crystallite size. The sizes of
NiO nanocrystals obtained from W–H analysis are well correlated with sizes
estimated using Scherrer’s formula. The relatively low saturation magnetization
of NiO confirms its super paramagnetic behavior.