Synthesis, crystal structure and optical spectra of Europium borate fluoride Eu_5(BO_3)_3F

摘要

Europium borate fluoride, Eu_5(BO_3)_3F, was synthesised as a single-phase crystalline powder starting from europium, oxide, europium, fluoride and boron oxide at: 1370 K. Eu_5(BO _3)_3F crystallises in the space group Pnma. Optical spectroscopy (emission and absorption) on Eu_5(BO_3) _3F confirms the presence of Eu~(2+) and delivered no evidence for Eu~(3+). The vibrational spectra of Eu_5(BO _3)_3F are also reported.