Temperature dependence of Nd3+→Yb3+ energy transfer processes in co-doped oxyfluoride glass ceramics

A study of the Nd3+ -> Yb-3 energy transfer processes in transparent oxylluoride glass ceramics has been carried out as a function of temperature in the 100-700 K range. This host is a two-phase optical material that consists of a low-phonon energy fluoride nanocrystalline phase embedded in a predominantly alummosilicate glassy medium and has shown to be an interesting matrix for rare earth ions. Luminescence decay curves of single Nd3+ and Yb3+ doped and co-doped samples at different temperatures have been analyzed in order to calculate the energy transfer and backtransfer rates between these ions. Finally, the results have been also investigated to known the phonons involved in the energy transfer processes, concluding at the end that the Nd3+ -> Yb3+ energy transfer rate takes place by the emission of three phonons with energy around 325 cm(-1) and in the other hand, Nd3+ -> Yb3+ energy transfer rate has been found to be non-negligible for temperatures over 370 K with the requirement of absorption of phonons. (c) 2007 Elsevier B.V. All rights reserved.