Confusion between Raman spectrum and luminescence : a case study of Eu³⁺ in Cs₂NaEuCl₆

Abstract

Some lanthanide ions have electronic energy levels extending from the far infrared to the vacuum ultraviolet. Without cross-relaxation between levels and other nonradiative depopulation mechanisms, and with adequate spacing between the energy levels, luminescence can be observed. When recording a Raman spectrum of a lanthanide compound, care should be taken to select an appropriate wavelength to avoid luminescence. Two recent examples illustrate results when this is not followed. Graphical abstract: [Figure not available: see fulltext.]