Photonic crystals in biology - NanoTR-VI

Poster Session, Thursday, June 17Theme F686 - N1123Optical and Structural Characterization of Y 2 O 3 :Nd 3+ Phosphors via Thermal Decomposition MethodG. Bilir* and G. ÖzenDepartment of Physics, stanbul Technical University, Maslak-stanbul 34469, TurkeyAbstract: The Y 2 O 3 :Nd 3+ nanophosphors were synthesized by using thermal decomposition method. The powders were annealed at differenttemperatures to investigate annealing temperature dependence of the crystallite size. Average particle size of the products were calculated byusing Scherrer Formula from the X-ray diffractograms Luminescence measurement were performed for all samples at room temperature. AlsoSEM/EDS measurements were confirmed the calculated particle sizes from XRD diffractograms.Materials with nanostructure attracted considerable attentionbecause of potential applications in optoelectronics andphotonics[1-4]. Phosphor materials find wide applicationsranging from fluorescent lamp to luminescence immunoassay.These materials essentially convert one type of energy intovisible radiation and hence, phosphor materials are calledoptical transducer[5].In this work nanosized Y 2 O 3 samples doped with x=0.2, 0.5,1, 2, 5, 10 mol% Nd 3+ ions (Y 2-x Nd x O 3 ) were prepared bythermal decomposition of yttrium-neodymium alginate.Obtained products were annealed at 600, 800 and 1000 toinvestigate particle size dependence on annealing temperature.X-ray diffraction investigations were carried out withPhilips TM model(Cu-K) diffractometer at 40 kV in the 2 rangefrom 20 o to 60 o . Also SEM images of the samples were taken byusing JEOL 6335F model scanning electron microscope(SEM).Both of XRD and SEM measurements show that the particlesizes of Y 2 O 3 :Nd 3+ samples were ranging from 20nm to 40 nmwhich are consistent with the values reported in literature[6].Representative X-ray diffractograms and SEM images are givenin Figs.1-2.Princeton Instruments SP2500i model monochromator andActon series ID441-C Model InGaAs detector for thedetection.PL measurements were performed at room temperature andstrong PL intensities were obtained for all Nd 3+ dopedsamples. The PL spectra of all samples are consist of threespectral regions which were correspond to the 4 F 3/2 4 I 9/2 ,4 F 3/2 4 I 11/2 and 4 F 3/2 4 I 13/2 transitions of theNd 3+ . In Fig.2representative of PL of 0.5% Nd 3+ doped sample are given.Figure 3: PL of 0.5% Nd 3+ doped Y 2O 3Also in Fig. 4, the dependence of FWHM(full width at halfmaxima) of the transitions on annealing temperature is given.Figure 1: XRD patterns of the non-annealed Y 2O 3:Nd 3+ nanopowdersFigure 2: SEM images of the %0,5Nd doped Y 2O 3 annealed at 1000C (left) andnon-annealed (right)From SEM images also seen that the organiccomponent(alginate) from synthesis method which used toform yttrium alginate gels is exist for non-annealed samplesand it was observed for all samples. The emission spectra werecollected by using Apollo Instruments diode laser (Model No:S30-808-6) with 805.2 nm wavelength as an excitation source,Figure 4:Annealing temperature dependence of the FWHMSEM measurements were supported by Science Institute ofMarmara University with the project number FEN-CDRP-090409-0079*bilirg@itu.edu.trReferences[1]Promod and et al, Journal of Luminescence, 82 (1999) 187-193[2] Hai Huang and et al, Nanotechnology, 13 (2002) 318-323[3] Gino Tessari, Marco Bettinelli and et al., Applied Surface Science,144-145 (1999) 686-689[4] Michael Nazarov and et al, Optical Materials, 27 (2005) 1587-1592[5] T. Kim Anh and et al, Journal of Luminescence, 102-103 (2003)391-394[6] D. Tatar, H. Kaygusuz, F. Tezcan, FB. Erim, ML. Oveçolu, G.Ozen “Y2O3 Nanophosphors Synthesized by Combustion and ThermalDecomposition Techniques” 11th Annual Conference on NanoScienceand NanoTechnology, NSTI-NanoTech, Boston-USA (MO81-919)(June 1-5/2008)6th Nanoscience and Nanotechnology Conference, zmir, 2010 617