Umesh, B. and Eraiah, B. and Nagabhushana, H. and Sharma, SC and Nagabhushana, BM and Shivakumara, C and Rao, JL and Chakradhar, RPS (2012) Structural, EPR, optical and Raman studies of Nd2O3:Cu2+ nanophosphors. In: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 94 . pp. 365-371.
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Nanocrystalline Nd2O3:Cu2+ (2 mol %) phosphors have been prepared by a low temperature solution combustion technique. Powder X-ray diffraction (PXRD) results confirm that hexagonal A-type Nd2O3 (900 degrees C, 3 h) and the lattice parameters have been evaluated by Rietveld refinement. Surface morphology of as-formed and Cu2+ doped Nd2O3 phosphors show that the particles are irregular in shape and porous in nature. TEM results also confirm the nature and size of the particles. The EPR spectrum exhibits two resonance signals with effective g values at g(parallel to) approximate to 2.12 and g(perpendicular to) approximate to 2.04. The g values indicate that the site symmetry of Cu2+ ions is octahedral symmetry with elongated tetragonal distortion. Raman studies show major peaks, which are assigned, to F-g and combination of A(g) + E-g modes. It is observed that the Raman peaks and intensity have been reduced in Cu2+ doped samples. UV-Visible absorption spectra exhibit a strong and broad absorption band at similar to 240 nm. Further, the absorption peak shifts to similar to 14 nm in Cu2+ doped samples. The optical band gap is estimated to be 5.28 eV for Cu doped Nd2O3 nanoparticles which are higher than the bulk Nd2O3 (4.7 eV). This can be attributed to the quantum confinement effect of the nanoparticles. (C) 2012 Elsevier B.V. All rights reserved.
|Item Type:||Journal Article|
|Additional Information:||Copyright for this article belongs to Elsevier|
|Keywords:||Nanoparticles; PXRD; SEM; TEM; EPR; Raman; Optical properties|
|Department/Centre:||Division of Chemical Sciences > Solid State & Structural Chemistry Unit|
|Date Deposited:||02 Aug 2012 05:34|
|Last Modified:||02 Aug 2012 05:34|
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