X-ray luminescence properties of rare-earth doped orthotantalate

This paper reports the X-ray luminescence emission spectra of YTaO4 and GdTaO4 activated by rare-earth ions. The luminescence efficiency of M'-type YTaO4 activated by rare-earth ions was calculated. An assumption model was used to explain the luminescent properties under X-ray excitation. The model assumes that the TaO43- group absorbs all the excitation energy, then transfers part of the energy to rare-earth ions, followed by emission of rare-earth ions. The calculation results agree with experimental results for M'-type YTaO4 activated by Sm3+, Tb3+, and Dy3+. M'-type YTaO4:Eu3+ is an exception because EU3+ may be involved in the process of energy absorption. (C) 2001 Elsevier Science Ltd. All rights reserved.