Goerigk, Felix C.Paterlini, VeronicaDorn, Katharina V.Mudring, Anja-VerenaSchleid, Thomas2024-04-022024-04-0220202073-43521885094280http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-141740http://elib.uni-stuttgart.de/handle/11682/14174http://dx.doi.org/10.18419/opus-14155Pale yellow crystals of LnSb2O4Br (Ln = Eu-Tb) were synthesized via high temperature solid-state reactions from antimony sesquioxide, the respective lanthanoid sesquioxides and tribromides. Single-crystal X-ray diffraction studies revealed a layered structure in the monoclinic space group P21/c. In contrast to hitherto reported quaternary lanthanoid(III) halide oxoantimonates(III), in LnSb2O4Br the lanthanoid(III) cations are exclusively coordinated by oxygen atoms in the form of square hemiprisms. These [LnO8]13- polyhedra form layers parallel to (100) by sharing common edges. All antimony(III) cations are coordinated by three oxygen atoms forming ψ1-tetrahedral [SbO3]3- units, which have oxygen atoms in common building up meandering strands along [001] according to {[SbO𝑣2/2O𝑡1/1]-}-1 (v = vertex-sharing, t = terminal). The bromide anions are located between two layers of these parallel running oxoantimonate(III) strands and have no bonding contacts with the Ln3+ cations. Since Sb3+ is known to be an efficient sensitizer for Ln3+ emission, photoluminescence studies were carried out to characterize the optical properties and assess their suitability as light phosphors. Indeed, for both, GdSb2O4Br and TbSb2O4Br doped with about 1.0-1.5 at-% Eu3+ efficient sensitization of the Eu3+ emission could be detected. For TbSb2O4Br, in addition, a remarkably high energy transfer from Tb3+ to Eu3+ could be detected that leads to a substantially increased Eu3+ emission intensity, rendering it an efficient red light emitting material.eninfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/4.0/540article2023-11-14