Lehlohonolo F. Koao; Setumo V. Motloung; Tshwafo E. Motaung
Abstract
LiMn2O4 (LMO) powders were prepared by modified chemical bath deposition method. The effect of reaction time on the structure, morphology and optical properties of LMO nanostructures were investigated. The reaction time was varied from 1 - 120 min. The X-ray diffraction (XRD) patterns of the powders ...
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LiMn2O4 (LMO) powders were prepared by modified chemical bath deposition method. The effect of reaction time on the structure, morphology and optical properties of LMO nanostructures were investigated. The reaction time was varied from 1 - 120 min. The X-ray diffraction (XRD) patterns of the powders correspond to the various planes of a cubic spinel LMO phase. It was observed that the secondary phases decreases with an increase in reaction time. The diffraction peaks increase in intensity with an increase in reaction time up to 10 min. The estimated average grain sizes calculated using the XRD spectra were found to be in the order of 60 ± 1 nm. The scanning electron microscope (SEM) image suggested that the reaction time influences the morphology of the prepared powders. The irregular nanoparticle increased in size with an increase in reaction time. The UV-Vis spectra showed a red shift with an increase in reaction time up to 10 min.
Lehlohonolo F. Koao; Birhanu F. Dejene; Hendrik C. Swart; Setumo V. Motloung; Tshwafo E. Motaung; Shanganyane P. Hlangothi
Abstract
Tb3 + doped ZnO nanoparticles were synthesized using the chemical bath deposition (CBD) method at 80 ºC. All the samples were annealed at 700 ºC to remove the hydroxyl groups confirmed by the thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA). The thermal analysis, ...
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Tb3 + doped ZnO nanoparticles were synthesized using the chemical bath deposition (CBD) method at 80 ºC. All the samples were annealed at 700 ºC to remove the hydroxyl groups confirmed by the thermogravimetric analysis (TGA) and differential thermogravimetric analysis (DTGA). The thermal analysis, structure, morphology and optical properties were characterized. The TGA and DTGA showed that the final yield decreases with an increase in the amount of molar concentration of Tb3 + ions. The X-ray diffraction (XRD) spectra of the ZnO: Tb3 + nanoparticles correspond to the various planes of hexagonal ZnO phase for the lower and higher Tb concentration samples. The estimated average grain sizes calculated using the XRD spectra were found to be in the order of 44 ±2 nm. The grain size was found to increase with an increase in the amount of Tb3+ ions. Scanning electron microscopy (SEM) micrographs showed nanoparticles are obtained for undoped ZnO and emergence of pyramids shape for higher molar concentration of Tb3 + ions. The reflectance spectra depict a red shift with an increase in Tb3 + molar concentration. Photoluminescence (PL) results showed that the luminescence intensity increased with an increase in the amount of Tb3 + ions.