Abstract : A strong green emission of U/sup 3+/ ions in LaCl/sub 3/ under red excitation has been observed for the first time. The main anti-Stokes fluorescence arises from the U/sup 3+2/K/sub 15/2/ state (around 550 nm). Theoretical analysis and decaytime measurement of the induced fluorescence show that there are two mechanisms for the up-conversion. The first one consists in excited state absorption and the other one is due to energy transfer between two U/sup 3+/ ions in the /sup 4/F/sub 9/2/ state. In addition a detailed study of infrared emission spectra of LaCl/sub 3/:U/sup 3+/ has been carried out and lifetimes of main fluorescent levels were measured at low temperature. From this study three new experimental levels have been assigned.
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Submitted on : Tuesday, April 18, 2000 - 10:37:55 AM Last modification on : Wednesday, September 16, 2020 - 4:07:23 PM
M. Yin, M.F. Joubert, J.C. Krupa. Green up-conversion and infrared emission spectra of U$^{3+}$ in LaCl$_3$/. Journal of Alloys and Compounds, Elsevier, 1997, 260, pp.64-69. ⟨in2p3-00022975⟩