So despite of the increase of the density of non-bridging oxygen’s with TiO2 content, which normally increases the Urbach energy [35], the local order in the glass can compensate such effect and contribute to a reduction of Eu.
So despite of the increaseof the density of non-bridging oxygen’s with TiO2 content, whichnormally increases the Urbach energy [35], the local order in theglass can compensate such effect and contribute to a reduction ofEu.