Luminescence and non-radiative processes in lanthanide squarate hydrates
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
27/05/2014
27/05/2014
01/11/1996
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Resumo |
The luminescence properties of solid hydrated lanthanide squarates (Ln2(C4O4)3(H2O) x; x = 8 or 13;Ln3+ = Gd, La, Eu, Tb, Pr) are reported for temperatures down to 4.2K. The luminescence of the squarate group is observed for the Gd3+ and La3+ compounds at low temperatures (below 150K). The Pr3+ compound does not show any emission at all, not even at 4.2K. This is ascribed to the quenching of the Pr3+ emission by multiphonon relaxation and/or concentration quenching. The quantum efficiencies of the 5D0 emission of Eu3+ and of the 5D4 emission of Tb3+ in these squarate complexes are strikingly different. Whereas the Tb3+ emission shows a temperature independent quantum efficiency of 50% upon ligand excitation, the Eu3+ emission is strongly quenched, showing a temperature dependent quantum efficiency of 0.8% at 4.2K upon ligand excitation. This quenching is ascribed to the low energy position of the charge-transfer state of Eu3+ in these compounds. |
Formato |
1727-1734 |
Identificador |
http://dx.doi.org/10.1016/0022-3697(96)00032-7 Journal of Physics and Chemistry of Solids, v. 57, n. 11, p. 1727-1734, 1996. 0022-3697 http://hdl.handle.net/11449/64869 10.1016/0022-3697(96)00032-7 WOS:A1996VU48100023 2-s2.0-0030284950 |
Idioma(s) |
eng |
Relação |
Journal of Physics and Chemistry of Solids |
Direitos |
closedAccess |
Palavras-Chave | #A. inorganic compounds #D. luminescence #D. optical properties #Charge transfer #Hydrates #Ions #Luminescence #Optical properties #Quantum efficiency #Quenching #Concentration quenching #Lanthanide squarate hydrates #Ligand excitation #Multiphonon relaxation #Nonradiative processes #Rare earth compounds |
Tipo |
info:eu-repo/semantics/article |