Zinc-doped yttrium oxide nanopowders of various doping concentrations have been successfully synthesized by simple methods like sol-gel, solvothermal and wetchemical methods. Structural property is analysed by X-ray powder diffraction (XRD). The presence of elements is confirmed by FTIR studies. Conductivity and dielectric behaviour of the samples are analysed by impedance spectroscopy. The effects of doping concentration and method of preparation on the crystallinity, the dielectric constant and the electrical properties of zinc-doped Y 2 O 3 nanomaterials are investigated and presented in this paper. XRD analysis shows the crystalline nature of the samples except the one prepared by solvothermal method. Also, the same sample is found to have more conductivity in the order of 5.04×10 −7 Scm −1 when compared with the samples prepared by other methods and of different doping concentration.

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Yttrium oxide (Y2O3) is the most familiar yttrium compound, which is popularly known as host for ion doping of other rare earth elements. Bismuth ion (Bi 3+ ) is well known as an activator and sensitizer in several particular phosphors. Zinc oxide (ZnO) nanomaterial, having a wide band gap, is one of the promising candidates for general illumination applications due to its high optical transparency and color tenability bismuth (Bi) and zinc (Zn) co-doped Y2O3 samples are synthesized by simple precipitation techniques like solvothermal and wet chemical methods. The prepared samples were characterized using X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectra, ultraviolet-visible absorbance spectroscopy and photoluminescence spectrophotometry. Ultraviolet-visible absorption studies showed absorption only around 340 nm whereas photoluminescence shows peaks around 500 nm, 680 nm, and 1020 nm for Bi and Zn co-doped Y2O3. The photoluminescence spectrum shows emission in blue region (500 nm) due to Zn dopant and red and near infrared region (680 and 1020 nm) due to Bi dopant. This is a new material which can effectively work as an efficient and cheap red phosphor.

Silver nanoparticles are known to have antimicrobial activity. The green synthesis method of nanoparticle synthesis is one of the most cost effective and eco friendly method. The present study is based on the synthesis of silver nanoparticles by the self reduction of silver nitrate by the leaf extracts of Vitex negundo which is one of the novel methods used in developing nanoparticles. The characterization of the particle was done by UV-Vis spectrophotometer, Fourier Transform Infra Red Spectroscopy, X-ray Diffraction analysis and the size of the synthesized nanoparticle was analyzed in the Scanning Electron Microscopy. The size of the particle was found to be 56 nm. The obtained silver nanoparticles showed anti-microbial activity against E.coli and Klebsiella pneumonia.

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