Effect of different fuels on structural, thermo and photoluminescent properties of Gd2O3 nanoparticles

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2012-10, Vol.96, p.532-540
• Main Authors: Dhananjaya, N., Nagabhushana, H., Nagabhushana, B.M., Rudraswamy, B., Sharma, S.C., Sunitha, D.V., Shivakumara, C., Chakradhar, R.P.S.
• Format: Article
• Language: English
• Subjects: Nanoparticles; Photoluminescence; Rare earth oxide; Solution combustion; Thermoluminescence
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2012.04.067

Packing diagram of cubic Gd2O3 prepared by citric acid as a fuel. [Display omitted] ► Gd2O3 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. Gd2O3 nanoparticles (27–60nm) 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 structural and luminescence properties have been carried out using powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman, UV–Vis, photoluminescence (PL) and thermoluminescence (TL) techniques. The optical band gap values were estimated 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 4.89–5.59eV. 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 270nm excitation, deep blue UV-band at ∼390nm along with blue (420–482nm), green (532nm) and red emission (612nm) was observed. The 390nm 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 Gd2O3 prepared by different fuels by irradiating with γ-rays (1kGy). 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.