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http://dx.doi.org/10.18419/opus-12852
Autor(en): | Buyer, Constantin Enseling, David Jüstel, Thomas Schleid, Thomas |
Titel: | Hydrothermal synthesis, crystal structure, and spectroscopic properties of pure and Eu3+-doped NaY[SO4]2 ∙ H2O and its anhydrate NaY[SO4]2 |
Erscheinungsdatum: | 2021 |
Dokumentart: | Zeitschriftenartikel |
Seiten: | 22 |
Erschienen in: | Crystals 11 (2021), No. 575 |
URI: | http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-128717 http://elib.uni-stuttgart.de/handle/11682/12871 http://dx.doi.org/10.18419/opus-12852 |
ISSN: | 2073-4352 |
Zusammenfassung: | The water-soluble colorless compound NaY[SO4]2 ∙ H2O was synthesized with wet methods in a Teflon autoclave by adding a mixture of Na2[SO4] and Y2[SO4]3 ∙ 8 H2O to a small amount of water and heating it up to 190 °C. By slow cooling, single crystals could be obtained and the trigonal crystal structure of NaY[SO4]2 ∙ H2O was refined based on X-ray diffraction data in space group P3221 (a = 682.24(5) pm, c = 1270.65(9) pm, Z = 3). After its thermal decomposition starting at 180 °C, the anhydrate NaY[SO4]2 can be obtained with a monoclinic crystal structure refined from powder X-ray diffraction data in space group P21/m (a = 467.697(5) pm, b = 686.380(6) pm, c = 956.597(9) pm, β = 96.8079(5), Z = 2). Both compounds display unique Y3+-cation sites with eightfold oxygen coordination (d(Y-Os = 220-277 pm)) from tetrahedral [SO4]2− anions (d(S-O = 141-151 pm)) and a ninth oxygen ligand from an H2O molecule (d(Y-Ow = 238 pm) in the hydrate case. In both compounds, the Na+ cations are atoms (d(Na-Os = 224-290 pm) from six independent [SO4]2- tetrahedra each. Thermogravimetry and temperature-dependent PXRD experiments were performed as well as IR and Raman spectroscopic studies. Eu3+-doped samples were investigated for their photoluminescence properties in both cases. The quantum yield of the red luminescence for the anhydrate NaY[SO4]2:Eu3+ was found to be almost 20 times higher than the one of the hydrate NaY[SO4]2 ∙ H2O:Eu3+. The anhydrate NaY[SO4]2:Eu3+ exhibits a decay time of about τ1/e = 2.3 µm almost independent of the temperature between 100 and 500 K, while the CIE1931 color coordinates at x = 0.65 and y = 0.35 are very temperature-consistent too. Due to these findings, the anhydrate is suitable as a red emitter in lighting for emissive displays. |
Enthalten in den Sammlungen: | 03 Fakultät Chemie |
Dateien zu dieser Ressource:
Datei | Beschreibung | Größe | Format | |
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crystals-11-00575-v4.pdf | 9,92 MB | Adobe PDF | Öffnen/Anzeigen |
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