400 resultados para Eu2 ions
Resumo:
MAIF5MCaSrBaLIMAIFaMCaSrCaAIFSrAIFBaAICaAIF6LrAISrAlF5LiSrAlF6llCoAIF6BaAlF5LiCaAlF6KMgF3:EuKMgFa:EU6P7/28S7/2420nml6P7/2-8S7/2Eu3+GdEuKMgFaBaLiF3BaY2F8Gd2+Eu2+Gd3+Eu2+Gd3+Eu2+Pr+ KMgF2LiYF4BaY2F8KMgFa:Pr3+352nmPr3+KMg1-xCaxF3Pr3+Ca2MgSi2O2EuEu3+Eu2+Ca2Eu8Si6O26X-ray
Resumo:
4fN-1n'l'4fN-1n'l'6604fN-1n'l'n'l'=5d6s6p4fN-1n'l'fN-15d4fN-15dfdhe[fciaiQi2]1/2Dy3+Tb3+fCe3+Eu2+4fN-15dheheCe3+Ey2+4fN-15dCe3+Eu2+4fN-15dFcEhQfi/NFc10Dq4fN-15dCe3+Eu2+heFc4fN-1n'l
Resumo:
Here we report the electron migration by photo- or thermostimulation in BaFCl:Eu2+. Electrons released from F centers may be trapped by other defect sites to form F aggregates or another type of F center and vice versa. This migration reduces the photostimulated luminescence efficiency, lowers the imaging plate sensitivity, and causes the difference between the optical absorption and photostimulation spectra of color centers. (C) 1997 American Institute of Physics.
Resumo:
In the photoluminescence (PL) of BaFBr:Eu2+,Eu3+, the emissions of Ea(2+), carrier electron-hole (e-h) recombination, and Eu3+ are observed, while in the photostimulated luminescence (PSL) only the emission of Eu2+ is exhibited. This disappearance of e-h recombination in PSL is considered to be caused by carrier migration during photo-stimulation. (C) 1997 American Institute of Physics.
Resumo:
After x-irradiation for 10 s, luminescence from BaFBr:Eu2+ phosphors by photostimulation of longer wavelength than F absorption bands was observed and assigned to the surface states or intrinsic defects of the powders. It is found that the luminescence by photostimulation into F bands can be reduced via electron migration from F centers into the surface states or intrinsic defects, thus reducing the x-ray storage or image stability. Surface passivation can lower these defects and improve the phosphors or imaging plate quality. (C) 1996 American Institute of Physics.
