Influence of Li doping on structural, electrical, optical and magnetic properties of Zn0.96Mn0.04O nanocrystals
文摘
In this paper, we report on the influence of Li doping on the structural, morphological, electrical, optical and magnetic properties of Zn0.96−xMn0.04LixO (for x = 0.02, 0.03, 0.04) nanocrystals synthesized by a simple low-temperature co-precipitation method. Rietveld refinement of the XRD patterns confirmed single phase Wurtzite type hexagonal structure of the nanoparticles and expansion in the lattice cell volume with increasing content of Li. TEM images reveal formation of hexagon shaped nano-crystals and also show a good agreement with the crystallite size estimated from the XRD analysis. The I–V characteristics show that resistivity of the samples decreases with increasing Li concentration. The UV–Vis-NIR absorption studies show a reduction in optical energy band gap than that reported for pure ZnO which decreases gradually with increasing Li concentration, showing a qualitative agreement with the I-V characteristic results. Magnetization measurements show clear evidence of weak ferromagnetic ordering at room temperature, which increases with Li content. The observed ferromagnetism seems to show close correlation with the oxygen vacancy defects induced by Li doping.