Annealing effects on the microstructure of combustion synthesized Eu3+ and Tb3+ doped Y2O3 nanoparticles

Eu3+ and Tb3+ doped Y2O3 powders having different Eu3+/Tb3+ concentrations were prepared by gel-combustion process using glycine as fuel (reducing agent) and corresponding metal nitrates as oxidant, followed by annealing at 600 and 1200 °C. From XRD, SEM and TEM studies, it is inferred that for these samples, the extent of aggregation and average particle size strongly depends on the annealing temperatures. Small angle X-ray scattering (SAXS) studies on these samples revealed that the scattering intensity at large values of momentum transfer vector (Q) vary as Q−4, establishing the lack of surface fractal nature as well as existence of a non-diffusive and smooth pore grain interface in both 600 and 1200 °C annealed samples. Dopant ions up to 10 at.% do not have any effect on particle/pore morphology of the samples. Improved luminescence from 1200 °C heated sample compared to 600 °C heated sample has been explained based on the difference in particle size and associated difference in the surface area.

► There is no surface fractal nature observed with Y2O3:Eu,Tb nanoparticles.
► Existence of non-diffusive and smooth pore grain interface in the nanoparticles.
► Particle size significantly affects luminescence from the nanoparticles.