Synthesis, structural characterization and optical properties of Ce, Eu and Tb doped strontium pyroborate nanoparticles

In this study, undoped and Ce, Eu and Tb doped Strontium Pyroborate nanoparticles were successfully synthesized by using Solution Combustion Synthesis (SCS), as well as the structural and optical properties of as-prepared products were comparatively characterized by Infrared spectroscopy (FTIR), X-Ray Powder Diffraction (XRD), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-VIS). During the preparation process, Sr(NO3)2, H3BO3, glycine, Tb(NO3)3.5H2O, Eu(NO3)3.5H2O, and Ce(NO3)3.6H2O were used as the starting materials. The effect of temperature and dopant ion on the crystal structure of the products were examined. It was found that undoped and lanthanide element doped Sr2B2O5 nanopowders obtained at 900°C were crystallized in monoclinic structure by examining XRD patterns. The formation of Sr2B2O5 was also confirmed with FT-IR spectroscopy by analyzing the vibrational modes belong to boron-oxygen bonds that occurred between 625 cm-1 to 1450 cm-1. Through UV-visible diffuse reflectance spectroscopic studies, the absorbance and reflectance spectra of the products were only observed in the ultraviolet region depending upon the host material, Sr2B2O5. It was also detected that the optical band gap energies of the pyroborates synthesized were decreasing as the temperature increasing.