Artículos de revistas
DFT and synchrotron radiation study of Eu2+ doped BaAl2O4
Fecha
2012Registro en:
OPTICAL MATERIALS EXPRESS, WASHINGTON, v. 2, n. 4, p. 420-431, APR 1, 2012
2159-3930
Autor
Brito, Hermi Felinto de
Felinto, Maria Claudia França da Cunha
Holsa, Jorma
Laamanen, Taneli
Lastusaari, Mika
Malkamaki, Marja
Novak, Pavel
Rodrigues, Lucas C. V.
Stefani, Roberval
Institución
Resumen
The structural distortions resulting from the size mismatch between the Eu2+ luminescent centre and the host Ba2+ cation as well as the electronic structure of BaAl2O4:Eu2+(,Dy3+) were studied using density functional theory (DFT) calculations and synchrotron radiation (SR) luminescence spectroscopy. The modified interionic distances as well as differences in the total energies indicate that Eu2+ prefers the smaller of the two possible Ba sites in the BaAl2O4 host. The calculated Eu2+ 4f(7) and 4f(6)5d(1) ground level energies confirm that the excited electrons can reach easily the conduction band for subsequent trapping. In addition to the green luminescence, a weak blue emission band was observed in BaAl2O4:Eu2+,Dy3+ probably due to the creation of a new Ba2+ site due to the effect of water exposure on the host. (C) 2012 Optical Society of America