Structural and optical investigations of Nd3+doped Y2O3-SiO2 nanopowder

Abstract

The present investigation deals with the synthesis of Nd3+ doped Y2O3:SiO2 nanopowder around moderate annealing temperatures (450 °C & 850 °C) using sol gel technique. The X-ray diffraction technique was used for phase identification, structural analysis and grain size determination. FTIR spectra of the prepared powder were taken at room temperature in the range 400–4000 cm−1. The morphology of nanoparticles and particle size was confirmed by Transmission Electron Microscope. From structural investigations, initial development of crystalline phase of yttium oxide was obtained in sample S2 annealed at 450 °C. While in sample S3 due to high annealing temperature (850 °C), agglomeration occurred. In this agglomerated sample temperature quenching results thus suppress the luminescence. Therefore, we have reported the optical investigations of sample S2 only. It is also demonstrated that the addition of SiO2 as sintering agent could improve both the optical and structural properties.The optical absorption spectrum has been observed in the 200–600 nm range. The absorption spectrum of Nd3+ doped Y2O3-SiO2 powder depicts absorption edge in ultra-violet region (310 nm) with prominent peaks of neodymium ion (808 nm) in IR region. The band edge absorption wavelength has been used to estimate the band-gap energy of the prepared nanocomposite by Tauc's plot. The emission spectrum has been obtained using two different excitation wavelength (λex = 310 & 808 nm) in UV and NIR regions, respectively. Using λex = 310 nm, strong emission bands have observed in 500–600 nm correspond to Si-O/Y-O or may be due to composite formation. However, the photoluminescence emission corresponding to λex = 808 nm have been centered at 890, 1042 and 1275 nm was attributed to neodymium ion. The structural and optical investigations of Nd3+ doped Y2O3:SiO2 is of basic importance for better utilization of such nanopowder in the fabrication of photonic devices, catalytic systems, solid state lasers, opto-and micro-electronics, nanophosphours and optical fiber amplifiers etc.