Siddaramana Gowd G.,Materials Development Group |
Kumar Patra M.,Materials Development Group |
Songara S.,Materials Development Group |
Shukla A.,Materials Development Group |
And 3 more authors.
Journal of Luminescence | Year: 2012
Eu 3+ doped Y 2O 3 nanophosphors have been synthesized using the simple colloidal precipitation method. Doping of Eu 3+ ions in host yttria lattice has been achieved through slow re-crystallization process under wet-chemical conditions followed by annealing at high temperatures (300-1400 °C). The nanophosphors were characterized by using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and spectrofluorometer techniques. XRD analysis reveals formation of pure cubic phase of Y 2O 3 in samples annealed at 700°C or above. Further, the XRD data was successfully used to retrieve the crystallite size and size distribution from powder samples using the FW((1/5)/(4/5))M method. Crystallite size (11-50 nm) extracted from XRD has been found to be consistent with AFM measurements. The PL emission spectra of nanophosphors show bright red emission at 612 nm due to hypersensitive electric dipole (ED) 5D 0- 7F 2 transition of Eu 3+ ions in Y 2O 3 lattice. Further, photoluminescence studies indicate that optimum value of the Eu 3+ to get best luminescence properties is 12 at%. Surface conjugations of these nanophosphors with water soluble dextran biomolecules have also been performed. Surface conjugated rare earth nanophosphors have great potential for bio-applications. © 2012 Elsevier B.V. All rights reserved.