13709-46-1Relevant articles and documents
Lyon, William G.,Osborne, Darrell W.,Flotow, Howard E.
, p. 675 - 680 (1979)
Crystal structure, electronic structure, and luminescence of Cs 2KYF6:Pr3+
Schiffbauer, Daniel,Wickleder, Claudia,Meyer, Gerd,Kirm, Marco,Stephan, Michael,Schmidt, Peter C.
, p. 3046 - 3052 (2005)
The crystal structure, electronic states and VUV spectroscopic behaviour of Cs2KYF6 doped with Pr3+ ions have been investigated both by experimental and theoretical methods. Cs 2KYF6 (Fm3m, Z = 4, a = 945.5(3) pm, R1all = 0.0297) crystallizes with the cubic elpasolite type of structure. The local relaxation of the activator ions in the host lattices has been calculated by the projector augmented wave method (computer code VASP). The electronic states have been calculated using a spin density functional procedure based on the atomic sphere approximation (computer code ASW). VUV spectroscopic measurements show fast 4f1 5d1 → 4f2 emission of nanosecond duration as well as slow 4f2 → 4f2 emission depending on the excitation energy which indicates the occupation of different sites in the host lattice. This assumption was verified by a recently developed quantum mechanical method. The combination of the experimental and the theoretical results show that the Pr3+ ions are occupying three different sites, namely the Y3+ and the Cs+ site as well as the K+ site.
Infrared spectra and quantum chemical calculations of the bridge-bonded HC(F)LnF2 (Ln = La-Lu) complexes
Gong, Yu,Wang, Xuefeng,Andrews, Lester,Chen, Mingyang,Dixon, David A.
, p. 4443 - 4452 (2011/10/10)
Lanthanide metal atoms, produced by laser ablation, were condensed with CHF3 (CDF3) in excess argon or neon at 4 K, and new infrared absorptions are assigned to the oxidative addition product fluoromethylene lanthanide difluoride complex on the basis of deuterium substitution and density functional theory frequency calculations. Two dominant bands in the 500 cm-1 region are identified as metal-fluorine stretching modes. A band in the mid-600 cm-1 region is diagnostic for the unusual fluorine bridge bond C-(F)-Ln. Our calculations show that most of the bridged HC(F)LnF2 structures are 3-6 kcal/mol lower in energy than the open CHF-LnF2 structures, which is in contrast to the open structures observed for the corresponding CH2-LnF2 methylene lanthanide difluorides. Argon-to-neon matrix shifts are 15-16 cm -1 to the blue for stretching of the almost purely ionic Ln-F bonds, as expected, but 10 cm-1 to the red for the bridge C-(F)-Ln stretching mode, which arises because Ar binds more strongly to the electropositive Ln center, decreasing the bridge bonding, and thus allowing a higher C-F stretching frequency.
Branched NaYF4 nanocrystals with luminescent properties
Liang, Xin,Wang, Xun,Zhuang, Jing,Peng, Qing,Li, Yadong
, p. 6050 - 6055 (2008/10/09)
In this article, branched NaYF4 nanocrystals have been successfully synthesized via a simple hydrothermal method. On the basis of the analysis of HRTEM and TEM images, the growth modes of the branched structure and further branching behavior have been proposed. The up- and down-conversion luminescence of branched NaYF4:Er3+/Yb3+ and NaYF4:Eu3+ have been characterized. Multiarmed NaYF 4 phosphors can be introduced into polystyrene to form composite luminescent polymers because of its special geometrical shape. In conclusion, the luminescent branched particles should be of wide potential application as building blocks in the future nanoscience and nanotechnology.
