Luminescence of the elpasolite series MI2MIIMCl6 (MI=Cs, Rb; MII=Li, Na; M=Lu, Y, Sc, In) doped with europium using synchrotron radiation excitation

The excitation and emission spectra of a series of cubic hexachloroelpasolites doped with europium have been investigated using synchrotron radiation at 10 K. Besides the Eu3+ emission from 5DJ (J=0–3) multiplets, emission from 5H3 is also observed for Cs2NaIn0.995Eu0.005Cl6, since the gap to the next lowest level is spanned by seven phonons. The excitation spectra of samples indicate impurities due to oxygen and divalent europium. Broad band emission from Eu2+ is reported from the crystalline samples grown in vacuum by the Bridgman process, with the maximum wavelength shifting to the red with increasing lattice parameter for the series Cs2NaMCl6:Eu2+ (M=Lu, Y, Eu).

Graphical abstractLuminescence of Eu3+ and Eu2+ in elpasolite hosts under synchrotron radiation is observed and assigned.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of MI2MIIMCl6-doped with europium. ► 10 K spectra indicate broad bands due to Eu–O CT, Eu–Cl CT and Eu2+ transitions. ► Ultraviolet emission from the 3H5 level of Eu3+, not only restricted to fluorides. ► Correlation between Eu2+ emission maximum and host lattice parameter.