Energy levels of HoBr63−

Abstract The excitation, electronic absorption and luminescence spectra of cubic Cs 2 NaHoBr 6 have been recorded at temperatures down to that of liquid helium. The detailed spectral analyses enable comparisons to be made of the crystal-field splittings of Russell—Saunders terms with those in Cs 2 NaHoCl 6 . Under intense 647.1 nm laser excitation, luminescence is observed in the neat material in the spectral region between 17800 and 21750 cm −1 .