Fabrication of nano-crystalline undoped and some lanthanide ions (Eu³⁺ and Sm³⁺) doped calcium pyroborate ceramic powders.

In this study, nano-crystalline undoped and some lanthanide ion (Eu⁺ and Sm³⁺) doped calcium pyroborate ceramic powders production were successfully synthesized by solution combustion synthesis (SCS) method using calcium nitrate, boric acid, rare earth metals, and several fuels (urea, tartaric acid, glycine, citric acid and HMTA) as starting materials. Different concentrations of rare earth metals were applied such as Eu³⁺ (0.005, 0.01, 0.02, 0.05) and Sm³⁺(0.005, 0.01, 0.015). The characterization processes of products were analyzed using X-Ray Diffraction (XRD) and Infrared spectroscopy (FTIR). The impact of several fuel resources and annealing temperatures (400-900 °C) on the structural features of the synthesized products was examined by the XRD technique. Based on the XRD data, it was found that the single-phase alpha forms of undoped and lanthanide ion doped calcium pyroborates were fabricated at 900 °C with monoclinic crystal structure. Examining the FT-IR spectra, the bond variation of calcium pyroborates were observed at >1000 cm−1 assigned to the B–O stretching modes of the triangular [BO₃]3− . It was also determined that the bands betweeen 600 to 820 cm−1 originated from the bending vibrational motions of B-O bond of BO₃ groups.