Effect of different fuels on structural, thermo and photoluminescent properties of Gd 2 O 3 nanoparticles N. Dhananjaya a,b , H. Nagabhushana c,⇑ , B.M. Nagabhushana d , B. Rudraswamy a,⇑ , S.C. Sharma c , D.V. Sunitha c , C. Shivakumara e , R.P.S. Chakradhar f a Department of Physics, J.B. Campus, Bangalore University, Bangalore 560 056, India b Department of Physics, B.M.S. Institute of Technology, Bangalore 560 064, India c Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India d Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India e Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India f CSIR-National Aerospace Laboratories, Bangalore 560 017, India highlights " Gd 2 O 3 nanophosphors using citric acid, urea, glycine and oxalyl dihydrazide have been prepared. " Effects of fuel on structural and luminescence properties were investigated. " A well resolved TL glow peak at 230 °C was observed for all the samples. " Kinetic parameters were estimated using Chen’s peak shape method. graphical abstract Packing diagram of cubic Gd 2 O 3 prepared by citric acid as a fuel. article info Article history: Received 11 December 2011 Received in revised form 8 April 2012 Accepted 14 April 2012 Available online 3 May 2012 Keywords: Rare earth oxide Solution combustion Nanoparticles Photoluminescence Thermoluminescence abstract Gd 2 O 3 nanoparticles (27–60 nm) have been synthesized by the low temperature solution combustion method using citric acid, urea, glycine and oxalyl dihydrazide (ODH) as fuels in a short time. The struc- tural and luminescence properties have been carried out using powder X-ray diffraction (PXRD), trans- mission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman, UV–Vis, photoluminescence (PL) and thermoluminescence (TL) techniques. The optical band gap values were esti- mated for as formed and 800 °C calcined samples. The band gap values in as-formed and calcined samples were found to be in the range 4.89–5.59 eV. It is observed that, the band gap values are lower for as- formed products and it has been attributed to high degree of structural defects. However, in calcined samples, structure becomes more order with reduced structure defects. Upon 270 nm excitation, deep blue UV-band at 390 nm along with blue (420–482 nm), green (532 nm) and red emission (612 nm) was observed. The 390 nm emission peak may be attributed to recombination of delocalized electron close to the conduction band with a single charged state of surface oxygen vacancy. TL measurements were carried out on Gd 2 O 3 prepared by different fuels by irradiating with c-rays (1 kGy). A well resolved glow peak at 230 °C was observed for all the samples. It is observed that TL intensity is found to be higher in for urea fuel when compared to others. From TL glow curves the kinetic parameters were estimated using Chen’s peak shape method and results are discussed in detail. Ó 2012 Elsevier B.V. All rights reserved. 1386-1425/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2012.04.067 ⇑ Corresponding authors. Tel.: +91 9945954010 (M). E-mail addresses: bhushanvlc@gmail.com (H. Nagabhushana), brudraswamy@gmail.com (B. Rudraswamy). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 96 (2012) 532–540 Contents lists available at SciVerse ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa