Abstract
A facile and economical hydrothermal method was used to synthesize alpha-Fe2O3 and NiFe2O4 nanoparticles with cubic spinel structure. The crystallography and optical properties of the as-synthesized nanoparticles were studied using X-ray diffraction (XRD) and Photoluminescence spectroscopy (PL). The morphology of the nanoparticles was observed using scanning and transmission electron microscopies (SEM and TEM). X-ray diffraction confirms the formation of the cubic spinel crystal structure of NiFe2O4 nanoparticles with an average crystallite size of 10 nm. The obtained nanopowders presented agglomerated and spherical shaped nanoparticles as shown in SEM and TEM photographs. The hematite has three emission peaks located at 492, 528 and 588 nm. Both Ni-F25 and Ni-F50 samples present two emission peaks located at 538 and 568 nm. While Ni-F75 sample has two emission peaks located at 539 and 569 nm. These peaks might be assigned to the electronic transition in the conduction band of the hematite.