A COMPARATIVE STUDY OF THE STRUCTURAL AND OPTICAL PROPERTIES OF NIO NANOPARTICLES DOPED WITH CERIUM AND SAMARIUM

In the present work, nickel oxide nanoparticles, Ce doped nickel oxide nanoparticles and Sm doped nickel oxide nanoparticles are synthesized using the simple sol gel technique. The influence of doping of Ce and Sm (1.00 atomic %) on the crystalline structure and optical properties of NiO nanoparticles was investigated. The samples were characterized for structure, phase and morphology by XRD, EDAX and SEM techniques. The XRD patterns confirmed the formation of face centered cubic structure for undoped NiO nanoparticles, Ce doped NiO (CNO) nanoparticles and Sm doped NiO (SNO) nanoparticles. The average crystalline size of the as prepared samples were calculated and reported as were 27 nm for undoped NiO nanoparticles, 35 nm for CNO nanoparticles and 33 nm for SNO nanoparticles. The HallWilliamson analysis is used to estimate the average crystalline size and lattice strain induced due to the substitution of cerium and samarium in the prepared sample. The SEM images reveal spherical morphology with the formation of monosized particles. The optical properties were compared by measuring the band-gap energy with UV–visible spectroscopy technique. The band gap of CNO nanoparticles (3.5 eV) was found to be lower than that of the undoped NiO nanoparticles (3.61 eV) whereas for SNO nanoparticles (3.77 eV) it was found to be more than that of the undoped NiO nanoparticles (3.61 eV).