Recovery rate and homogeneity of doping europium into luminescent metal hydrides by chemical analysis†
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 EuxSr1−xH2 and applied to brightly emitting hydridic perovskites LiMH3:Eu2+ and LiMD3:Eu2+ (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 LiEuxSr1−xH3 with x = 0.0037% show a broad band emission at room temperature typical for Eu2+ 4f65d1–4f7 transitions. Below 80 K, a vibronic fine structure is observed with vibrational coupling frequencies of approximately 100, 370 and 970 cm−1.