Annealing and doping concentration effects on Y2O3: Sm3+ nanopowder obtained by self-propagation room temperature reaction

In this report, structure, morphology and luminescence of Y2O3:Sm3+ nanoparticles prepared by self-propagating room temperature reaction are presented. This new, simple and cost effective synthesis allows obtaining desired phase composition by mixing appropriate amounts of yttrium and samarium nitrates together with sodium hydroxide. A set of samples is prepared with different Sm3+ concentrations (0.1, 0.2, 0.5, 1 and 2 at %) in order to observe changes of luminescence properties. Also, effects of post synthesis annealing at several temperatures (600°C, 800°C and 1100°C) are analyzed. For all samples X-ray diffraction showed that powders have cubic bixbyite structure (Ia-3), and TEM analysis showed particles of less than 100 nm. Luminescence emission spectra clearly show peaks characteristic for electronic spin-forbidden transition of Sm3+ ions 4G5/2→6H5/2, 6H7/2 and 6H9/2 centered at 578, 607 and 654 nm, respectively. Emission lifetime values decrease with Sm3+ ion concentration increment, from 1.94 ms for 0.1 at% to 0.97 ms for 2 at%. In addition, enlargement of lifetime value is observed when thermal treatment is done at the highest temperature due to the elimination of luminescence quenching species from the surface of particles. [Projekat Ministarstva nauke Republike Srbije, br. 45020 i br. 171022