Structural properties and luminescence of rare-earth ions in transition-metal fluoride glasses

Abstract

The fluorescence of rare-earth ions RE³⁺ = Pr³⁺, Er³⁺ and Tm³⁺ has been compared in the transition-metal fluoride glass (36 mol% PbF₂–24 mol% ZnF₂–35 mol% GaF₃–5 mol% YF₃–2Al mol% F₃) doped with either REF₃ or RECl₃. For the phonon-sensitive radiative transition, the lifetime is prolonged at low RECl₃ concentrations because the phonon energy and/or electron coupling are reduced. For Pr³⁺, the doping with PrCl₃ increases the lifetime by 50% with respect to PrF₃ doping. These results suggest that the Cl⁻ ions remain in the coordination sphere of the RE³⁺ ions in the ReCl₃-doped glass after melting.

Acknowledgements

This research was supported by the French Réseau National de Recherche en Télécommunication under grant 00S0508/13, Fondo per gli Investimenti della Ricerca di Base (FIRB) ‘Nanotecnologie, microtecnologie, sviluppo integrato di materiali’ and Ministero dell’istruzione dell’Università e della Ricerca (MIUR) (Cofinanziamento progretti di ricerca di Interesse Nazionale (COFIN) 2002) ‘Materiali nanostrutturati per l’ottica integrata’ Italian projects.