Evolution of Optical Band Gap and Related Properties in Ni1−xCoxO Nanoparticles
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Ni1−xCoxO Nanoparticles with x varying from 0 to 0.05 were synthesized by co-precipitation method. The effect of Co concentration on the optical band gap and related properties of NiO nanoparticles were studied by UV–visible spectroscopy. UV–visible characterization of these samples indicated that the band gap of NiO decreased from 3.65 to 3.38 eV with increasing Co concentration from 0 to 5% in NiO. It has been reported that the band gap of ternary compounds show band gap bowing with composition instead of linear variation. In our case it is found to be ~ 5.28 ± 0.5 eV. The refractive index and electron polarizability with Co doping concentration in NiO is calculated from the band gap. Both the parameters found to increase with increasing Co concentration in NiO. This study suggests the usefulness of these materials for optoelectronic devices.
KeywordsNanoparticles UV–visible spectroscopy Band gap Refractive index
The author thanks Dr. N.C. Mishra, Ex-Professor of Physics, Utkal University for his encouragements and suggestions.
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