authors |
Ananias, D; Paz, FAA; Carlos, LD; Rocha, J |
nationality |
International |
journal |
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY |
author keywords |
Germanium; Rare earths; Lanthanides; Photoluminescence; Up-conversion |
keywords |
MICROPOROUS LANTHANIDE SILICATES; X-RAY PHOSPHORS; CRYSTAL-STRUCTURE; PHOTOLUMINESCENCE PROPERTIES; ABSOLUTE-CONFIGURATION; PHASE-TRANSITION |
abstract |
The hydrothermal synthesis and structural characterization of new trivalent rare-earth germanates, Na-4[(Y(1-a)Ln(a))(2)Ge4O13] (Ln = Eu, Tb, or Yb and Er; a = 0.05, 0.1) and Na-4[(Yb0.9Er0.1)(2)Ge4O13] are reported. The structure of these solids was solved by single-crystal X-ray diffraction (150 K). The materials crystallize in the orthorhombic non-centrosymmetric Pna2(1) space group, and exhibit a framework comprising unprecedented anionic tetrameric [Ge4O13](10-) units, tetrameric units of {GeO4} tetrahedra, and isolated dimeric units encompassing two distinct distorted {REO6} octahedra. These rare-earth germanates feature interesting photoluminescence properties in the visible and near-infrared spectral regions. Eu3+ photoluminescence confirms the presence of two distinct rare-earth sites. Energy transfer between the latter sites is shown for the Yb3+/Er3+ pair, both displaying significant near-infrared emission. Isomorphous Na-4[(Yb0.9Er0.1)(2)Ge4O13] features up-conversion emission, an unusual property among rare-earth crystalline germanates. |
publisher |
WILEY-V C H VERLAG GMBH |
issn |
1434-1948 |
year published |
2018 |
issue |
20-21 |
beginning page |
2444 |
ending page |
2451 |
digital object identifier (doi) |
10.1002/ejic.201800153 |
web of science category |
Chemistry, Inorganic & Nuclear |
subject category |
Chemistry |
unique article identifier |
WOS:000434220300036
|