Recovery rate and homogeneity of doping europium into luminescent metal hydrides by chemical analysisElectronic supplementary information (ESI) available: High resolution spectrum of LiSrH3:Eu2+ 0.0037 mol% at 4 K and assignment of the vibronics. See DOI: 10.1039/c4ra14076a

During the investigation of concentration dependent properties of phosphors, such as emission intensities, the knowledge of the activator ion concentration is of great importance. Herein we present a study on recovery rate and homogeneity of the activator ion concentration by chemical analysis in luminescent europium doped metal hydrides. The analysis method was established on the model system Eu x Sr 1− x H 2 and applied to brightly emitting hydridic perovskites LiMH 3 :Eu 2+ and LiMD 3 :Eu 2+ (M = Sr, Ba). The nominal activator ion concentrations calculated from initial weights are in good agreement with those determined via ICP-MS for 10 −3 % ≤ x both for the hydrides (deuterides) and the parent alloys. The synthesis protocol thus allows a reliable method for reproducibly doping europium into metal hydrides. Luminescence spectra of LiEu x Sr 1− x H 3 with x = 0.0037% show a broad band emission at room temperature typical for Eu 2+ 4f 6 5d 1 -4f 7 transitions. Below 80 K, a vibronic fine structure is observed with vibrational coupling frequencies of approximately 100, 370 and 970 cm −1 . A study on recovery rate and homogeneity of the activator ion concentration in luminescent europium doped metal hydrides and a reliable method for reproducibly doping europium are presented.