Local and medium range structure of erbium containing glasses: A molecular dynamics study

Erbium containing glasses cover an important role in optical communications and laser technology. The local environment of the ions constituting the three dimensional network exerts a strong influence on the chemical and physical properties of the glasses. In particular the network modifier cations strongly influence the short and intermediate range order of the glass structure. The structural modifications induced by the alumina addition in the glass matrix, as a function of the erbium oxide concentration, have been studied using molecular dynamics (MD) simulations. While at low Er2O3 concentration the network former action of the Al3+ leads to a more polymerized glass network, at higher Er2O3 content the influence of the alumina on the erbium local structure is limited. Further investigation points out micro-heterogeneity in the Na+ and Ca2+ distribution as a function of the alumina concentration.