TY - JOUR A1 - Yusenko, Kirill A1 - Kabelitz, Anke A1 - Schokel, Alexander A1 - Wagner, Ralf A1 - Prinz, Carsten A1 - Kemnitz, E A1 - Emmerling, Franziska A1 - Krahl, Thoralf A1 - de Oliveira Guilherme Buzanich, Ana T1 - Local Structure of Europium-Doped Luminescent Strontium Fluoride Nanoparticles: Comparative X-ray Absorption Spectroscopy and Diffraction Study N2 - Rare-earth based luminescent materials are key functional components for the rational design of light-conversion smart devices. Stable Eu3+-doped strontium fluoride (SrF2) nanoparticles were prepared at room temperature in ethylene glycol. Their luminescence depends on the Eu content and changes after heat treatment. The crystallinity of heat-treated material increases in comparison with as-synthesized samples. Particles were investigated in solution using X-ray diffraction, small-angle X-ray scattering, and X-ray spectroscopy. After heat treatment, the size of the disordered nanoparticles increases together with a change of their local structure. Interstitial fluoride ions can be localized near Eu3+ ions. Therefore, non-radiative relaxation from other mechanisms is decreased. Knowledge about the cation distribution is key information for understanding the luminescence properties of any material. KW - SrF2 KW - EXAFS KW - Eu PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-540094 DO - https://doi.org/10.1002/cnma.202100281 VL - 7 IS - 11 SP - 1221 EP - 1229 PB - Wiley Online Library AN - OPUS4-54009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zänker, Steffen A1 - Scholz, Gudrun A1 - Krahl, Thoralf A1 - Prinz, Carsten A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - Luminescent properties of Eu3+/Tb3+ doped fluorine containing coordination polymers N2 - Lanthanides doped coordination polymers (CPs) with different binding motifs were synthesized to investigate the influence of the different fluorine positions in the structure on the decay time τ of the excited states. Fluorine can be integrated into the network mechanochemically via a fluorinated organic linker, here barium tetrafluoroterephthalate Ba(p-BDC-F4)2 or directly via a metal-fluorine bond (barium terephthalate fluoride BaF(p-BDC)0.5). The CP with a metal-fluorine bond shows the highest lifetime of the excited states of lanthanides (Eu3+, Tb3+ or Eu3+& Tb3+). The excitation of the lanthanides can be performed directly via the excitation wavelength typical for lanthanides and via the excitation wavelength of the linker. This enabled the simultaneous excitation of Eu3+ and Tb3+ in one CP. In the emission spectra (λem = 393 nm) of the mixed doped CPs (Eu3+ and Tb3+) the bands of both lanthanides can be observed. The integration into the crystal lattice and the homogeneous distribution of the lanthanides in the CPs is shown by X-ray diffraction, TEM, STEM-EDS measurements and the long decay times. KW - Alkaline earth metal coordination polymers KW - Fluorine coordination polymers KW - Lanthanides doped coordination polymers KW - Luminescence PY - 2021 DO - https://doi.org/10.1016/j.solidstatesciences.2021.106614 VL - 117 SP - 106614 PB - Elsevier Masson SAS AN - OPUS4-52559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -