Structure and optical properties of Eu 3+-doped fluoroaluminate and fluorophosphate glasses

Abstract

Emission spectra of Eu 3+ in fluoroaluminate and fluorophosphate glasses at 80 K were measured as a function of excitation energy by the fluorescence line narrowing (FLN) technique. The magnitudes of the splitting of the 7F 1 manifolds at lower excitation energies increased with increasing phosphate content. The relative intensity of 5D 0 → 7F 2 to 5D 0 → 7F 1 transitions increased by adding the phosphate compound. This increase decreased gradually with increasing excitation energy. The atomic structure around Eu 3+ in these glasses was simulated using molecular dynamics techniques. The Stark splitting and the transition probabilities between 5D 0 and 7F J energy states at each simulated Eu 3+ ion were calculated on the basis of the point-charge approximation. The predicted energy differences between 5D 0 and ( 7F 2, 7F 1 and 7F 0) energy levels agree within 100 cm −1 with the observed ones. The transition probabilities are discussed in terms of the crystal field potential and the configuration interaction parameters, Ξ( k, λ).