title: Alkaline-earth metal hydrides as novel host lattices for Eu(II) luminescence.
abstract: Luminescence of divalent europium has been investigated for the first time in metal hydrides. A complete solid-solution series was found for the pseudobinary system Eu(x)Sr(1-x)H(2) [a = 637.6(1) pm -12.1(3)x pm, b = 387.0(1)-6.5(2)x pm, c = 732.2(2)-10.1(4)x pm]. Europium-doped alkaline-earth hydrides Eu(x)M(1-x)H(2) (M = Ca, Sr, Ba) with a small europium concentration (x = 0.005) exhibit luminescence with maximum emission wavelengths of 764 nm (M = Ca), 728 nm (M = Sr), and 750 nm (M = Ba); i.e., the emission energy of divalent europium shows an extremely large red shift compared to the emission energies of fluorides or oxides. Theoretical calculations (LDA+U) confirm decreasing band gaps with increasing europium content of the solid solutions.
authors.affiliation: FR 8.1 Fachrichtung Chemie, Universität des Saarlandes, Postfach 151150, 66041 Saarbrücken, Germany.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Kunkel
authors.forename: Holger
authors.initials: H
authors.lastname: Kohlmann
authors.forename: Adlane
authors.initials: A
authors.lastname: Sayede
authors.forename: Michael
authors.initials: M
authors.lastname: Springborg