Effect of annealing on the structural and optical properties of pristine and cerium doped calcium tungstate nanoparticles synthesized via hydrothermal method

Abstract

The work is an investigation of the effect of annealing temperature on pristine and rare earth doped CaWO4 nanoparticles with hydrothermal route. The sample was annealed at two varied temperatures 800 ºC and 1200 ºC for 5 h. The structural analysis reveals the reduction in the broadening of the peaks as a result of annealing. Surface morphology shows the formation of agglomerated structures. In Ce3+:CaWO4 nanoparticles the morphology is modified to dumbbell like and flake like structures after annealing. Raman shift observed at 909 cm−1 Ag modes confirms the presence of CaWO4 nanoparticles with its own rotational and vibrationalmodes. Increase in the absorption peak intensity and a double absorption edge appears as an intermediate energy level state after the inclusion of Ce3+ ion as dopant.