Browsing by Author "Kalengay, M."

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    Influence of transition metal doping on the structural and optical properties of iron chromium nano oxides
    (University of Namibia, 2019) Kalengay, M.; Nsio, Tony N.; Osman, N.S.
    We have synthesized Sn0.2Fex Cr1.8 – xO3 nano oxides with x= 0.0, 0.1, 0.2, 0.3. Single phase corundum structure and nanophase structure of the as-synthesized samples were confirmed by X-ray diffraction (XRD) and by transmission electron microscope (TEM). Crystallite sizes were calculated using the Scherrer’s formula whilst particle sizes were obtained by TEM and found to be varying from 27.06 to 32.05 nm for the samples synthesized at different iron content. The optical measurements were performed by UV-visible spectroscopy. We observed that the band gaps and the refractive index vary with iron content.
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    Structural and optical studies of tin iron chromium nano oxides
    (University of Namibia, 2019) Kalengay, M.; Nsio, Tony N.
    In the present study, we have synthesized Sn0.2Fe0.9Cr0.9O3 nano oxides. Single phase corundumlike structure and nanophase structure of the as-synthesized sample were confirmed by x-ray diffraction (XRD) and by transmission electron microscope (TEM). The results show that the produced powders have grain size of approximately 32 nm. Using the result of the ultraviolet-visible (UVVis) spectrometer, we were able to determine the energy band gaps of 3.1 and 5.2 eV , when nanoparticles are diluted in iron standard solution and in deionised water respectively.