摘要

The Eu2O3-PbO-SiO2 glassy system submitted to a long annealing time (100 ps) has been obtained by molecular dynamics calculations. The average of 87/86 sites of the Eu3+ ion with six/seven nearest neighbours are used to discuss the number of lines and the local symmetry of the luminescent site through the crystal field parameters, using the simple overlap model in the frame of the method of equivalent nearest neighbours. The magnitude of the B-q(2) (q = 0, 1, 2) and the non-negligible B-4(4) and B-4(6)(B-3(4), B-3(6) and B-6(6)) lead to the indication of distorted Ca and C-4h site symmetries of the six and seven nearest neighbours, respectively. We have then compared very satisfactorily our 7F1 sublevels calculations with those observed in the emission spectra of an Eu-borate glass annealed for 30 min and 17 h. This comparison is justified because the emission behaviour of europium ions in different glassy systems are honestly very similar. Further, the decrease observed in the D-5(0)-> F-7(2)/D-5(0) -> F-7(1) transition intensity ratio is a clear indication that the Eu3+ ion are nucleating a crystalline phase. Such satisfactory comparisons indicate that we have obtained a transparent glass-ceramics.

  • 出版日期2016-9-15